ALBERT

Description: Legumes fix atmospheric nitrogen by symbiosis with soil bacteria in root nodules. Legume yields are limited by the low capacity of N 2 fixation. Hypernodulating mutants have been selected decades ago to try to increase nodule number. However, literature data show that N fixation of hypernodulating mutants was not increased compared to parental lines. Here, we study the functional basis of limited N fixation associated to hypernodulation. We grew two wild type genotypes and nine hypernodulating mutants of pea in hydroponics in three greenhouse experiments. We measured the following traits related to N nutrition during the vegetative period: nodule number, plant N uptake, nodule-specific activity, and plant and nodule concentrations. Genetic and environmental variations induced nodule gradients. These gradients were used to set quantitative relationships between N nutrition traits and nodule number. We compared the relationships obtained for hypernodulating and for wild types. N nutrition traits were analysed together with C nutrition traits, through correlation networks. Our results show that higher nodule number of hypernodulating mutants is correlated with lower levels of nodule activity, from −25 to −60 %, by comparison to the wild type. Higher nodule number of hypernodulating mutants is also correlated with lower total N uptake by symbiotic fixation, from −0 to −60 %, by comparison to the wild type. Findings demonstrate that N nutrition is not a factor limiting growth in hypernodulating mutants, as shown by N nutrition index higher than 1, indicating N nutrition in excess. The correlations suggest that limited N 2 fixation in hypernodulating mutants arises from restricted shoot growth, which limits the plant capacity to accumulate N. Furthermore, symbiotic efficiency decreased with increasing nodule number, down to a minimal value for hypernodulating mutants. Thus, to overcome the trade-off between N benefits from N 2 fixation and carbon nodulation costs, the hypernodulation trait should be associated with high shoot growth capacity in breeding programs.

Description: Environmental and economic issues affect decision-making for whether or not to control small infestations of pests and pathogens in crops. Even where no crop yield loss is expected, other risks may be evident, such as the slow accumulation of pathogen inocula. The prevalence of toxins, arising from biotic interactions with fungal diseases, can alter crop quality rather than quantity. Thus, farmer decisions for whether to tolerate pest infestation must take into account several direct and immediate and/or delayed potential risks. Published scientific evidence on the co-occurrence of risk factors resulting from the presence of different pests and pathogens are largely absent, and this has stifled the adoption of integrated pest management. Here, we tested how the withdrawal of herbicide and insecticide protection in maize, alone and in combination, might induce higher prevalence of up to 23 mycotoxins in the crop at harvest. The experiment was conducted over 4 years in 29 fields in the south west of France. The test involved a comparison of paired samples collected from treated and untreated plots. All nine major mycotoxins that were observed in more than 4 % of the samples showed highly variable concentrations both between fields and years. The overall trend following the cessation of pesticide protection, however, is for higher levels of mycotoxins and up to a six-fold increased in nivalenol mean concentration (to 202.3 μg kg −1 of maize seeds) compared to its treated control. Overall mycotoxin concentrations approached 55–67 % of their maximum acceptable rate, a situation of reduced security margin that could lead to economic penalties and market restrictions. We found that the removal of herbicides had a greater impact than that of insecticides on the prevalence of mycotoxins, which differs from the expectation stated in the literature. This finding is further reinforced by the observation that certain species of weeds harbor several species of Fusarium . This means that weeds not only play a role as crop competitors but also as reservoirs of inoculum in the field. Our findings illustrate the importance of sanitary evaluation when the implementation of new cropping systems will alter the distribution and occurrence of pests and pathogens.

Description: Biofortification is a strategy for overcoming human zinc (Zn) deficiency, especially in rural areas of developing countries. Actually, biofortification by foliar Zn application has been demonstrated at small scale, but not at large scale due to the absence of economic analysis. Therefore, here, we conducted the first cost-effectiveness analysis using the method of “disability-adjusted life year” measuring the health burden. We thus quantified the cost of agronomic biofortification of wheat with Zn in three major wheat-growing regions of China. Our results show that the current annual health burden due to human Zn deficiency, defined as numbers of disability-adjusted life years lost, is 0.21 million years for the region under single wheat plantation, 0.79 million years for the region under wheat-maize rotation, and 0.38 million years for the region under wheat-rice rotation. Comparing with traditional wheat diets in these three regions, the consumption of agronomically Zn-biofortified wheat diets could increase the daily Zn intakes of infants and children under 5 years of age. These increased daily Zn intakes consequently reduce the health burden due to human Zn deficiency in these regions by up to 56.6 %. According to cost-effectiveness analysis, the cost for saving one disability-adjusted life year in these regions ranges from US$ 226 to US$ 594 for foliar Zn application alone. The cost ranges from US$ 41 to US$ 108 when foliar Zn and pesticide applications are combined to reduce labor costs. This cost of US$ 41–108 under the combined application of foliar Zn plus pesticide is lower than the World Bank’s standard.

Description: Integrated weed management aims to decrease the dependence of cropping systems on herbicides by using a combination of several agricultural practices. Environmental impacts of individual practices under various conditions are already known. However, there is scarce knowledge on the impact of combining several practices. Therefore, we studied N 2 O emissions of weed management cropping systems that use differing practices such as crop diversity, tillage, and herbicide pressure, during about 1 year. Data were compared with a conventionally managed cropping system. Results were also simulated using the NOE model. Results show a large variation of N 2 O emissions, ranging from 177 g N 2 O-N/ha for intensive tillage integrated weed management to 362 g N 2 O-N/ha for the conventional cropping system, 777 g N2O-N/ha for the no herbicide cropping system and 5226 g N 2 O-N/ha for no-till integrated weed management. Most N 2 O emissions occurred in spring, despite the absence of fertilizing related N 2 O peaks. The lowest emissions occurred in autumn and winter. Emissions are explained by interactions between specific soil potential denitrification rate, soil bulk density, temperature, soil water, and inorganic N contents. N 2 O emissions are accurately predicted by the model NOE, with a global Nash-Sutcliffe coefficient of efficiency equal to 0.80.

Description: Many tree crop farms in the tropics are in a process of crop diversification, even in regions that have traditionally been dominated by a single tree crop species. Here, we review the factors that drive diversification and that influence farmer choices. We analyze recent literature from tropical Latin America, Africa, Asia, and the Pacific Islands, with emphasis on West and Central Africa. We use a framework that distinguishes farmer objectives in diversifying; the opportunities and constraints caused by environmental, technological, market, and policy factors; and farmer characteristics. Our main findings are: (1) Farmers diversify to increase their income by adding more lucrative crops. They diversify also to spread their income to lean times between the harvests of their traditional crops. In addition, farmers diversify to maintain or increase their food security especially while young tree crops are maturing and to reduce their vulnerability to environmental, market, and policy shocks. (2) Famers take advantage of opportunities and are subject to constraints. These include: heterogeneous site characteristics; the legacy of previous forest vegetation; emergent market opportunities from growing urban centers; a diversity of products and market outlets for some crops that reduces marketing risks; government policies; labor constraints that favor certain crops; the availability of investment capital that influences particularly the timing of diversification decisions; and access to improved planting material. (3) Diversification decisions also depend on farmer characteristics such as their age, education, financial situation, and farm and family size. Young farmers are not always more active in diversification than older farmers, although diversification and crop change are often related to generational change. Returning urban migrants have often had a positive effect in terms of diversification and innovation. (4) Diversification is often a response to structural environmental degradation caused by decades of tree crop monocultures. We conclude with a list of areas where government and non-government organizations can support farmers in their diversification decisions.

Description: This report shows that weed harrowing in organic cereal fields is an efficient alternative to herbicides since weed harrowing does not reduce yields compared to weed-free plots. Arable weeds provide resources and habitat to many organisms. However, weeds are the most important constraint to crop production. Indeed, the potential crop losses of the eight major crops due to weed–crop competition amount to about 30 %. New ways of food production are needed due to the current severe biodiversity decline, about 1,000 times higher than the natural rate of species loss, and the growing food demands. Herbicides are highly efficient at reducing crop losses due to weed–crop competition, but at the expense of declining biodiversity. Studies have shown a poor efficiency of weed harrows in terms of weed reduction in organic farming systems. Here, we evaluated the feasibility of weed harrows in organic fields to reduce weeds to a threshold that does not limit crop production, while maintaining a rich flora. The results were compared to results obtained using herbicides in conventionally managed fields. Eleven organic and conventional cereal field pairs in Catalonia, Spain, were evaluated for one season in 2006–2007. Three different weed control treatments were applied: weed-free plots; weed-controlled plots, using herbicide in conventional fields and weed harrowing in organic ones and non-weeded plots. Crop yield and the abundance, richness and composition of the weed flora, which was dominated by ryegrass and poppies, were evaluated. Our results show that weed harrowing prevents weeds from being a limiting factor of crop productivity in organic cereal fields, since weed-controlled plots did not reduce yields compared to weed-free plots. A similar trend was observed in herbicide-controlled plots. However, herbicides diminished weed species richness in approximately 47 % and changed the species composition whereas harrowing allowed the maintenance of high levels of weed diversity in the organic fields.

Description: The growing demand for food poses major challenges to humankind. We have to safeguard both biodiversity and arable land for future agricultural food production, and we need to protect genetic diversity to safeguard ecosystem resilience. We must produce more food with less input, while deploying every effort to minimize risk. Agricultural sustainability is no longer optional but mandatory. There is still an on-going debate among researchers and in the media on the best strategy to keep pace with global population growth and increasing food demand. One strategy favors the use of genetically modified (GM) crops, while another strategy focuses on agricultural biodiversity. Here, we discuss two obstacles to sustainable agriculture solutions. The first obstacle is the claim that genetically modified crops are necessary if we are to secure food production within the next decades. This claim has no scientific support, but is rather a reflection of corporate interests. The second obstacle is the resultant shortage of research funds for agrobiodiversity solutions in comparison with funding for research in genetic modification of crops. Favoring biodiversity does not exclude any future biotechnological contributions, but favoring biotechnology threatens future biodiversity resources. An objective review of current knowledge places GM crops far down the list of potential solutions in the coming decades. We conclude that much of the research funding currently available for the development of GM crops would be much better spent in other research areas of plant science, e.g., nutrition, policy research, governance, and solutions close to local market conditions if the goal is to provide sufficient food for the world’s growing population in a sustainable way.

Description: Agricultural practices affect the physical and chemical characteristics of the soil, which in turn may influence soil microorganisms with consequences on soil biological functioning. However, there is little knowledge on the interactions between agricultural management, soil physicochemical properties, and soil microbial communities, notably in tropical ecosystems with few studies conducted in strongly weathered and acid soils. Here, we investigated the early effect of tillage and crop residues management on top soil physical, chemical, and microbial properties in an acid savannah grassland of northeastern Laos. We initiated a 3-year rotation of rice/corn/soybean under three no-till systems (NTs) distinguished by the cover crops associated prior to and with the main crops, and one conventional tillage-based system (CT). The effect of agricultural management was evaluated 2 years after land reclamation in reference to the surrounding natural pasture (PAS). Our results demonstrate that NTs improve soil physicochemical characteristics (aggregate stability, organic carbon, and cation exchange capacity) as well as microbial abundance (total biomass, bacterial and fungal densities). A significant discrimination of the genetic structure of soil bacterial community was also observed between NTs, CT, and PAS. Interestingly, bacterial abundance and diversity were differently influenced by soil environment changes: microbial density was affected by the quantity and diversity of crop residues, soil organic carbon, and exchangeable base contents, whereas soil bacterial genetic structure was mainly determined by exchangeable aluminum content, pH, cation exchange capacity, and C/N ratio. Altogether, our study represents one of the most complete environmental evaluations of agricultural practices in tropical agrosystems and leads to recommend no-till systems with high residue restitutions to improve the physical, chemical, and microbial properties of tropical acid soils and thus contribute to the sustainability of agriculture in these ecosystems.

Description: Composts are potential substitutes of mineral fertilizers for sustainable agriculture. Composts are commonly applied to soil at high dose, e.g. from 20 to 30 t (dry matter) per ha and year, to compensate organic matter loss and nutrient depletion. Recently, amendment of soluble substances from urban compost at a much lower dose of 1.55 t per ha enhanced tomato productivity much more than the compost itself. Here, we studied the effect of soluble substances at 0–700 kg per ha on red pepper. We measured productivity, chlorophyll, and soil chemical composition. The most remarkable result is an observed maximum productivity for only 140 kg per ha of compost soluble substances. The increases amounted to 90 % for the precocious crop yield, to 66 % for the total crop production, and to 17 % for the per fruit weight. The discovery that the highest effects occur at such low treatment dose is very promising to enhance crop productivity in a sustainable way. No detectable change of soil chemical composition was observed.

Description: Ecosystems are increasingly manipulated for agricultural and conservation goals. Ecosystem functions need to be sustained socially and ecologically. New frameworks must be built to simulate agrosystems based on ecological processes instead of external chemicals. Food web structures of agrosystems highly influence their agronomical performance and stability. Although it has been observed that living communities are ruling the performance of agroecosystems, these living communities are generally ignored by agronomists who focused mainly on abiotic factors. Indeed, agronomists usually focus on the soil–plant–atmosphere continuum. Now, ecological modellers can link food web models with soil–plant models to create innovative frameworks. Here, we advocate that food webs must be included in simulations of production and in studies of emerging properties. We emphasize the role of trophic chains in the regulation of pests. Emerging properties include aboveground and belowground interactions, pest control, and positive feedbacks on soil properties. We propose a conceptual structure for this framework and discuss how the structure of linked food web/cropping system models can account for the specific properties of agroecosystems. The proposed structure includes a process-based approach to link food webs with crop models. Such comprehensive models address the issue of trade-offs between ecosystem services, including regulation of crop pests by the ecosystem community, nutrient cycling, and crop production.

Description: A major issue of potato cultivation in temperate zones is the potato cyst nematode Globodera rostochiensis . Population density of G . rostochiensis is high in Mexican potato fields. Control currently consists of the inefficient application of high doses of chemical nematicides. We evaluated the population density of G . rostochiensis in potato production plots in central Veracruz, Mexico. Plots were treated with the biocontrol agent Paecilomyces sp. and rotation with two different leguminous crop plants, Pisum sativum and Vicia faba . A random block experimental design was used with four different treatments over two crop cycles: (1) biological control with crop rotation, (2) crop rotation only, (3) biological control applied to soil left in fallow, and (4) soil left in fallow only. We measured the number and content of cysts, and the number of J2 juveniles of G . rostochiensis in the soil. We then estimated the infestation level in soil and the multiplication rate (Pf/Pi). The number of free-living nematodes was also quantified. Results show that the highest mitigation of G . rostochiensis was observed for the biological control rotation, with 89.2 % reduction, and for the biological control fallow treatments with 84.4 % reduction. In rotation plots, infestation level decreased by 30.7 %. In the biological control rotation and biological control fallow treatments, the Pf/Pi was 0.1 and 0.15, respectively. The highest Pf/Pi of 0.93 was found in the fallow plots. The biological control agent did not significantly affect the free-living nematode populations. In this study, the nematophagous fungus Paecilomyces sp. was used for the first time to efficiently reduce the population of G . rostochiensis in two crop cycles.

Description: To improve sustainability, farmers may want to redesign their livestock farming systems in depth. Systemic modelling has proved an efficient tool to study complex issues regarding farming systems, but it remains inefficient to support farmers in their system redesign processes. This paper describes and discusses a novel method to model livestock farming systems with groups of farmers to help them redesign their own systems. Modelling livestock farming systems at the farm scale with farmer groups is an original approach in livestock farming system modelling. Following a constructivist approach, our method involves working with farmers already involved in redesign processes and building causal maps according to their own representations, without using models previously created by scientists. Applying the method, we built two causal maps of livestock farming system operation, each one built with a group of five farmers including both those converting and converted to organic farming. Converting to organic farming was considered as one example of a redesign process. On the basis of a subjective assessment by both the participating farmers and researchers, and an analysis of map structures, we assessed the method’s strengths and weaknesses. We considered that one of its main advantages lay in its collective dimension: sharing, comparing and questioning interested the participating farmers greatly; however, it requires good facilitation skills and suitable group composition. Furthermore, the formalising process identified, for example, vicious circles in system operation, which made the farmers think about solutions for breaking them. Finally, analysis of map structures identified similarities and differences between the two groups that were discussed with both of them during a final workshop; this activity continued farmers’ self-reflection about their systems, which may help lead to innovative and more sustainable livestock farming systems.

Description: This report shows the results of the first multi-year spatially distributed sensitivity analysis carried out on two complex agroecological models. Wheat is the staple food of 1.5 billion people worldwide. Projected trends in wheat global demand reveal risks of food security over the next decades. Systems for large-area crop monitoring and yield forecasting are needed to support agricultural policies, especially in developing countries. Among those crop systems, the most sophisticated ones are based on crop simulation models. Published reports of sensitivity analyses performed on different crop models show that parameters related to leaf area expansion are often considered as the most important. Here we show that, on the contrary, photosynthesis parameters are more relevant under the conditions explored. We carried out the sensitivity analysis on the models WOFOST and CropSyst for wheat simulation in Morocco. Due to the high number of model runs to be performed, a two-step procedure was adopted: The Morris method was used to identify parameters with a negligible effect, and then the Sobol method was applied on remaining parameters. Environmental and management information were obtained from the European Commission MARS database. Our results show that photosynthesis parameters explained more than 75 % of the total output variance for CropSyst and more than 70 % for WOFOST. On the contrary, parameters related to leaf area expansion were less relevant. Geographical patterns shown by sensitivity analysis results under heterogeneous conditions can help breeders to select specific plant traits, in order to develop phenotypes suitable for specific conditions, e.g., varieties with a higher level of thermal adaptation in the Southern regions.

Description: Plant fertilization is a major issue in the context of increasing population and food risk, higher cost of fertilizers, and low target efficiency of traditional mineral fertilization practices. Alternatively, application of microbial inoculants to the soil can enhance the uptake of nutrients by plants and increase the efficiency of mineral fertilizers and manures. Encapsulation methods involve covering and protecting the microorganisms. Encapsulation of bacterial cells has been challenged and used mainly in the agricultural industry using processes, such as spray drying, interfacial polymerization, or cross-linking. Here, we review techniques for microbial inoculants and their benefits for sustainable agriculture. Techniques include fluidized bed, extrusion, molecular inclusion, coacervation, liposomes, ionic or inverse gelation, and oil-entrapped emulsion. Major topics discussed are formulation of microbial inoculants, conventional inoculants, bioencapsulation materials, bioencapsulation techniques, and future trends. We found that (1) conventional inoculant does not provide adequate protection for microorganisms. (2) Bioencapsulation improves the protection and controlled release of bacteria. (3) Sodium alginate is one of the most used products for the bioencapsulation of microorganisms. (4) The bioencapsulation of microbial inoculants is performed with the incorporation of an active ingredient into a matrix followed by a mechanical operation, and finally stabilization by a chemical or physical–chemical process. (5) Spray-drying process works on a continuous basis, low operating cost, and high quality of capsules in good yield, although the high temperature used in the process is not very appropriate for encapsulating non-spore-forming bacteria. 6) Fluid-bed process is a promising encapsulation technique for large-scale production in agricultural industry. (7) Ionic gelation is currently the most adequate method found to encapsulate bacteria. (8) Some advantages and drawbacks are found for each technique; therefore, the selection of suitable bioencapsulation method will depend on bacteria strain, cost, processing conditions, and handling.

Description: Intensive livestock farming has raised issues about environmental impacts and food security during the past 20 years. As a consequence, there is a strong social demand for sustainable livestock systems. Sustainable livestock systems should indeed be environmentally friendly, economically viable for farmers, and socially acceptable, notably for animal welfare. For that goal, many sustainability indicators and methods have been developed at the farm level. The main challenge is using a transparent selection process to avoid assessment subjectivity. Here, we review typologies of sustainability indicators. We set guidelines for selecting indicators in a data-driven context, by reviewing selection criteria and discussing methodological issues. A case study is presented. The selected set of indicators mainly includes (1) environmental indicators focusing on farmer practices; (2) quantitative economic indicators; and (3) quantitative social indicators with a low degree of aggregation. The selection of indicators should consider (1) contextualization to determine purpose, scales, and stakeholders involved in the assessment; (2) the comparison of indicators based on various criteria, mainly data availability; and (3) the selection of a minimal, consistent, and sufficient set of indicators. Finally, we discuss the following issues: topics for which no indicators are measurable from available data should explicitly be mentioned in the results. A combination of means-based indicators could be used to assess a theme, but redundancy must be avoided. The unit used to express indicators influences the results and has therefore to be taken into account during interpretation. To compare farms from indicators, the influence of the structure on indicator values has to be carefully studied.

Description: Over the last two decades, the impact of elevated CO 2 on crops has become a major issue in the context of climate change. Increasing CO 2 levels should modify the plant demand for nutrients, but precise effects on plant physiology are poorly known. Here, we studied the effect of ambient CO 2 at 400 μmol mol −1 and high CO 2 at 1,000 μmol mol −1 on safflower ( Carthamus tinctorius L.) at N levels from 25 to 175 kg ha −1 . Growth and physiology of safflower were assessed in pots in controlled enclosure chambers in a glasshouse. Overall results show that high CO 2 increased assimilation rate by +27 %, leaf area index (LAI) by +28 %, total above-ground dry weight by +51 %, and total above-ground dry weight by +43 % at harvest. High CO 2 reduced stomatal conductance by −29 % and transpiration rate by −18 %. At anthesis, results show that high CO 2 increases assimilation rate by +13 %, LAI by +2 %, and above-ground dry weight by +34 %. At anthesis, results also show that high CO 2 decreases leaf N and chlorophyll content.

Description: Pesticides are now occurring worldwide in almost all water resources, thus threatening the health of humans and other life. As a consequence, there is a strong social demand for designing safe cropping systems with less or no hazardous pesticides. Safe cropping systems can be designed now using pesticide transfer models. These models are mathematical tools that allow to predict the flow and concentration of pesticides in a field or a watershed. Here, we review the effects of agricultural practices on runoff, leaching, erosion, and drift from eight watershed models and nine field models. Our main findings are the following: (1) though models claim they account for practices, their effects cannot be represented. We present a method and four practice levels to assess the effects of practices in models, using tillage as an example. (2) The conceptual structure of the model highly influences the predicted distribution and transfer of pesticides. For instance, the pesticide levels remaining on the soil surface after plowing ranges from 0 % of the dose applied for the MIKE SHE–DAISY model to 100 % for GLEAMS, annAGNPS, SoilFug, and PestLCI. Only the Root Zone Water Quality Model (RZWQM) simulates pesticide interception by mulch during pesticide application. (3) Models should better take into account mulching, e.g., plastic, crop residues and associated crops, and other innovative practices. (4) A change in scale is needed for drift in watershed models. Here, topological watershed representations are the most promising way for upscaling the effects of practices. (5) Non-conservative calculations of pesticide interception by watershed mitigation structures (SWAT) should be carefully checked because these calculations underestimate the risk of pollution at the outlet. How models simulate practices will no longer be a secret for model users who apply our methodology and recommendations when selecting a model. We provide recommendations for improving tools to assess practices.

Description: Urban agriculture is increasingly popular for social and economical benefits. However, edible crops grown in cities can be contaminated by airborne pollutants, thus leading to serious health risks. Therefore, we need a better understanding of contamination risks of urban cultivation to define safe practices. Here we study heavy metal risk in horticultural crops grown in urban gardens of Bologna, Italy. We investigated the effect of proximity to different pollution sources such as roads and railways, and the effect of the growing system used, that is soil versus soilless cultivation. We compared heavy metal concentration in urban and rural crops. We focused on surface deposition and tissue accumulation of pollutants during 3 years. Results show that in the city, crops near the road were polluted by heavy metals, with up to 160 mg per kilogram of dry weight for lettuce and 210 mg/kg for basil. The highest Cd accumulation of up to 1.2 mg/kg was found in rural tomato. Soilless planting systems enabled a reduction of heavy metal accumulation in plant tissue, of up to −71 % for rosemary leaves.

Description: Pollution of agricultural ecosystems is due to the excessive use of mineral fertilizers and mass discharge of livestock manure. Therefore, there is a need for disposing manure safely, for instance by transforming manure into valuable compost. Traditional composting is, however, time-consuming with considerable nutrient losses. Vermicomposting is an alternative method, but so far, there are few quantitative evaluations of vermicomposting. We therefore compared vermicomposting and traditional composting of cattle manure with maize. Our results show that the amount of nutrients from vermicomposting is lower than that from traditional composting. Nonetheless, vermicomposting yielded 2172.0 kg of earthworms per hectare, which provided an additional income of US$4008.1 to farmers. Moreover, vermicomposting increased aboveground biomass by 7.7 % and maize grain yield by 18.3 %. The global output of vermicomposting was thus higher by 304 % due to higher grain yield and earthworm income.

Description: Sustainable agricultural development is fundamental to food security and poverty alleviation, notably in developing countries. Many development initiatives focus on the enhancement of smallholder production and productivity because the majority of poor people in developing countries live in rural areas where agriculture is the main source of livelihood. The consequences of these development initiatives need to be assessed before implementation to reduce the risk of possible negative impacts. This can be done by applying ex ante sustainability impact assessment. Here, we compare methods of assessment of sustainability impact for farming interventions. We review methodological approaches and verify whether the requirements of sustainability impact assessment theory are fulfilled. Our major points are the following: (1) main methodological approaches do not fulfill the requirements defined in the theoretical sustainability impact assessment discourse. (2) The active involvement of different stakeholder groups throughout the assessment process and the possibility of learning and exchange are fundamental to sustainability impact assessment. (3) The institutional dimension of sustainability is not yet sufficiently integrated. We therefore suggest institutional criteria and indicators to be also considered in the sustainability impact assessment framework. We argue that sustainability impact assessment, respecting the interactive involvement of all stakeholder groups throughout the whole process, is a compulsory element in project planning for a sustainable agricultural development in developing countries.

Description: The use of biophysical models in agroecology has increased in the last few decades for two main reasons: the need to formalize empirical knowledge and the need to disseminate model-based decision support for decision makers (such as farmers, advisors, and policy makers). The first has encouraged the development and use of mathematical models to enhance the efficiency of field research through extrapolation beyond the limits of site, season, and management. The second reflects the increasing need (by scientists, managers, and the public) for simulation experimentation to explore options and consequences, for example, future resource use efficiency (i.e., management in sustainable intensification), impacts of and adaptation to climate change, understanding market and policy responses to shocks initiated at a biophysical level under increasing demand, and limited supply capacity. Production concerns thus dominate most model applications, but there is a notable growing emphasis on environmental, economic, and policy dimensions. Identifying effective methods of assessing model quality and performance has become a challenging but vital imperative, considering the variety of factors influencing model outputs. Understanding the requirements of stakeholders, in respect of model use, logically implies the need for their inclusion in model evaluation methods. We reviewed the use of metrics of model evaluation, with a particular emphasis on the involvement of stakeholders to expand horizons beyond conventional structured, numeric analyses. Two major topics are discussed: (1) the importance of deliberative processes for model evaluation, and (2) the role computer-aided techniques may play to integrate deliberative processes into the evaluation of agroecological models. We point out that (i) the evaluation of agroecological models can be improved through stakeholder follow-up, which is a key for the acceptability of model realizations in practice, (ii) model credibility depends not only on the outcomes of well-structured, numerically based evaluation, but also on less tangible factors that may need to be addressed using complementary deliberative processes, (iii) comprehensive evaluation of simulation models can be achieved by integrating the expectations of stakeholders via a weighting system of preferences and perception, (iv) questionnaire-based surveys can help understand the challenges posed by the deliberative process, and (v) a benefit can be obtained if model evaluation is conceived in a decisional perspective and evaluation techniques are developed at the same pace with which the models themselves are created and improved. Scientific knowledge hubs are also recognized as critical pillars to advance good modeling practice in relation to model evaluation (including access to dedicated software tools), an activity which is frequently neglected in the context of time-limited framework programs.

Description: Biochars are new, carbon-rich materials that could sequester carbon in soils improve soil properties and agronomic performance, inspired by investigations of Terra Preta in Amazonia. However, recent studies showed contrasting performance of biochar. In most studies, only pure biochar was used in tropical environments. Actually, there is little knowledge on the performance of biochar in combination with fertilizers under temperate climate. Therefore, we conducted an experiment under field conditions on a sandy Cambisol near Gorleben in Northern Germany. Ten different treatments were established in 72-m 2 plots and fivefold field replicates. Treatments included mineral fertilizer, biogas digestate, microbially inoculated biogas digestate and compost either alone or in combination with 1 to 40 Mg ha −1 of biochar. Soil samples were taken after fertilizer application and maize harvest. Our results show that the biochar addition of 1 Mg ha −1 to mineral fertilizer increased maize yield by 20 %, and biochar addition to biogas digestate increased maize yield by 30 % in comparison to the corresponding fertilizers without biochar. The addition of 10 Mg ha −1 biochar to compost increased maize yield by 26 % compared to pure compost. The addition of 40 Mg ha −1 biochar to biogas digestate increased maize yield by 42 % but reduced maize yield by 50 % when biogas digestate was fermented together with biochar. Biochar-fertilizer combinations increased K, Mg and Zn and reduced Na, Cu, Ni and Cd uptake into maize. Overall, our findings demonstrate that biochar-fertilizer combinations have a better performance than pure fertilizers, in terms of yield and plant nutrition. Therefore, an immediate substitution of mineral fertilizers is possible to close regional nutrient cycles.

Description: Provisioning services, such as the production of food, feed, and fiber, have always been the main focus of agriculture. Since the 1950s, intensive cropping systems based on the cultivation of a single crop or a single cultivar, in simplified rotations or monocultures, and relying on extensive use of agrochemical inputs have been preferred to more diverse, self-sustaining cropping systems, regardless of the environmental consequences. However, there is increasing evidence that such intensive agroecosystems have led to a decline in biodiversity as well as threatening the environment and have damaged a number of ecosystem services such as the biogeochemical nutrient cycles and the regulation of climate and water quality. Consequently, the current challenge facing agriculture is to ensure the future of food production while reducing the use of inputs and limiting environmental impacts and the loss of biodiversity. Here, we review examples of multiple cropping systems that aim to use biotic interactions to reduce chemical inputs and provide more ecosystem services than just provisioning. Our main findings are the identification of underlying ecological processes and management strategies related to the provision of pairs of ecosystem services namely food production and a regulation service. We also found gaps between ecological knowledge and the constraints of agricultural practices in taking account of the interactions and possible trade-offs between multiple ecosystem services as well as socioeconomic constraints. We present guidelines for the design of multiple cropping systems combining ecological, agricultural, and genetic concepts and approaches.

Description: Food production is highly dependent on regional yields of crops. Regional differences in grain yields could be due to fertilizer management and climate variability. Here, we analyze trends of grain yields in North China, Northeast China, East China, and Central and Southwest China from 1992 to 2012, using the Chinese statistical yearbooks. We estimate the major factors influencing yield by regression analysis. Results show that fertilizer indices were 40 % for Northeast China, 36 % for East China, 9 % for North China, and 6.8 % for Central and Southwest China. Soil indices were 67 % for Northeast China, 14 % for East China, 90 % for North China, and 6 % for Central and Southwest China. The indices of annual mean temperature were positive for Central and Southwest China (72 %) and East China (39 %), but negative for Northeast China (−15 %) and North China (−16 %). Soil factors explained 80 % of yield variation in North China. Annual mean temperature explained 80 % of yield variation in Central and Southwest China.

Description: Selecting a method for identifying actual crop productivity constraints is an important step for triggering innovation processes. Applied methods can be diverse and although such methods have consequences for the design of intervention strategies, documented comparisons between various methods are scarce. Different variables can be used to characterize these methods. To typify them, we used two of these variables in a heuristic model: control over the research process and represented opinion. Here, we review 16 published papers that present outcomes of different methods to identify productivity constraints. The major findings are the following: (1) Variation in methods is wide. (2) Applying the heuristic model results in three main clusters of methods: farmer-control/farmer-opinion, scientist-control/scientist-opinion, and scientist-control/farmer-opinion. (3) These clusters are scale level dependent. As a follow up, we compared in a case study the three different methods, representative for the three main clusters of the heuristic model, in order to assess their congruency. These methods (focus group discussion, individual surveys, and contextual data collection) were applied in four localities in Tigray, Northern Ethiopia. We found that congruency between the methods, as indicated by Spearman-ρ correlations, was not significant. In addition, we found that outcomes of individual surveys and contextual data collection among the different locations were correlated (R 〉 0.70). No such correlation was found using focus group discussion. Both findings indicate that for a specific location different methods yielded different constraints and that variability between the locations is not reflected by using individual surveys and contextual data collection. Combined the review and case study demonstrate that process control and represented opinion have a manifest impact on generated outcomes. Because outcomes of productivity constraints assessments are methodology dependent, researchers are recommended to justify a priori their choice of method using the presented heuristic model.

Description: Recently, nicotine has been detected in a large number of food crops and plant-derived products such as spices and herbal teas, but the origin of this nicotine is unknown. This study aimed to elucidate the putative sources of nicotine. We investigate the uptake of nicotine from nicotine-contaminated soils and tobacco smoke using peppermint plants, Mentha × piperita , as a model system in mulching and fumigation experiments. Results show that all the peppermint plants contain minor amounts of nicotine before treatment, but the experiments revealed that the plants also incorporate nicotine considerably from the soil as well as from tobacco smoke. These findings demonstrate for the first time that the reported occurrence of nicotine indeed may originate from tobacco. The incorporated nicotine was subsequently metabolised by the plants. Apart from the nutritional aspects, the results on nicotine uptake may also affect basic plant biology, because they demonstrate that alkaloids can be transferred from one plant, after its death, to another plant species.

Description: Farming activities in the Argentinean Pampa have focused on soybean production since the 1990s. The resulting cropping systems may not be sustainable in the long run due to development of glyphosate-tolerant weeds, homogenization of landscape mosaics, and pollutions. Here, we used the tracking on-farm innovation method to produce resources for the design of alternatives. The five steps of tracking on-farm innovation were (1) characterization of the soybean-based dominant cropping system, (2) identification of producers developing alternative systems, (3) description of these cropping systems and their agronomic logic, which is the link between the producer practices and their motives when choosing these practices, (4) multicriteria assessment of the performances of the systems, and (5) analysis of the development conditions of the most efficient systems. We identified 22 alternative cropping systems developed by farmers. These systems all include original practices: diversification of crop rotations (22 cases), occasional return to tillage (15 cases), and low pesticide use (16 cases). Some alternative systems were more sustainable than the soybean-based system, as shown by lower economic risk level, better ability to maintain soil organic carbon content, and less glyphosate-tolerant weeds. Our results show overall that tracking on-farm innovations is an efficient method to get references on alternative cropping systems developed by farmers.

Description: Agriculture consumes more than two thirds of the total freshwater of the planet. This issue causes substantial conflict in freshwater allocation between agriculture and other economic sectors. Regulated deficit irrigation (RDI) is key technology because it helps to improve water use efficiency. Nonetheless, there is a lack of understanding of the mechanisms with which plants respond to RDI. In particular, little is known about how RDI might increase crop production while reducing the amount of irrigation water in real-world agriculture. In this review, we found that RDI is largely implemented through three approaches: (1) growth stage-based deficit irrigation, (2) partial root-zone irrigation, and (3) subsurface dripper irrigation. Among these, partial root-zone irrigation is the most popular and effective because many field crops and some woody crops can save irrigation water up to 20 to 30 % without or with a minimal impact on crop yield. Improved water use efficiency with RDI is mainly due to the following: (1) enhanced guard cell signal transduction network that decreases transpiration water loss, (2) optimized stomatal control that improves the photosynthesis to transpiration ratio, and (3) decreased evaporative surface areas with partial root-zone irrigation that reduces soil evaporation. The mechanisms involved in the plant response to RDI-induced water stress include the morphological traits, e.g., increased root to shoot ratio and improved nutrient uptake and recovery; physiological traits, e.g., stomatal closure, decreased leaf respiration, and maintained photosynthesis; and biochemical traits, e.g., increased signaling molecules and enhanced antioxidation enzymatic activity.

Description: Deforestation of tropical forests for the establishment of grass monoculture for livestock production is responsible for about 30 % of CO 2 emissions. This issue is particularly severe in degraded pastures because degraded soils favor CO 2 flow to the soil surface. Silvopastoral systems could reduce CO 2 emissions, notably by using live fences. Here, we hypothesized that live fences of Gliricidia sepium in livestock systems should reduce variations in environmental relative humidity and soil temperature and, in turn, reduce soil CO 2 emissions. Here, we studied two livestock systems: (1) grass monoculture of Brachiaria decumbens with live fences of G. sepium and (2) grass monoculture of B. decumbens without live fences. We measured soil CO 2 seasonal emissions at different times of the day, soil temperature, and environmental relative humidity. Nine 600-m 2 plots were established in each system. All variables were measured over four 6-h period during a 24-h period, twice a month from April to September. Our results show that soil CO 2 emissions showed less variability with G. septum live fences than without live fences. This lower variability is explained by the creation of a microclimate with a higher and more stable environmental relative humidity, provided by the shade of trees. Results also show, however, that global soil CO 2 emissions did not differ between the two systems, with and without live fence. Moreover, soil CO 2 emissions varied according to season, as shown by 1.082 g CO 2 m −2  h −1 in the wet season versus 0.871 g CO 2 m −2  h −1 in the dry season. Soil CO 2 emissions varied also according to sampling time, as shown by 1.116 g CO 2 m −2  h −1 in the night versus 0.960 CO 2 m −2  h −1 in the morning.

Description: Agriculture is undergoing profound transformation in response to the global challenges of food security, pollution and climate change. In particular, some farmers are exploring and tentatively applying new practices based on agroecological principles. However, depending on biological regulation, these practices have uncertain results. In order to choose and monitor their changes, farmers use various indicators. In our study, we examined these indicators as they were applied in the implementation of technical changes, with a view to determining their exact nature, partly unexplored by agronomists. We held six interviews, performed a retrospective analysis of a redesign project involving five farmers and four advisors, observed collective visits at long-term field experiments, and organized a design workshop with eight farmers. We then coded the verbatim transcript in order to characterize the functions and attributes of the indicators, using the principles of grounded theory. Our results show that indicators have 22 different functions regarding the farmers’ technical action, grouped into five categories. The most common functions are more learning-oriented than assessment-oriented, e.g., “adaptation-monitoring” with 92 out of the 260 statements on indicators identified, and “understanding-reinterpretation” with 107 out of 260 statements. The attributes of the indicators are predominantly visual (62 %), relative (63 %), and passive (75 %). In addition, we found that indicators used at a strategic decision level are specific, as they are mostly quantified, concern large time and spatial scales, and are essentially dynamic, that is, interpreted in as trends.

Description: Safflower is one of the oldest cultivated crops, usually grown at a small scale. Safflower is grown for flowers used for coloring, flavoring foods, dyes, medicinal properties, and livestock feed. Safflower is underutilized but gaining attention due to oil yield potential and the ability to grow under high temperatures, drought, and salinity. Salinity and drought have negative effects by disrupting the ionic and osmotic equilibrium of the plant cells. The stress signal is perceived by membranes then transduced in the cell to switch on the stress responsive genes. This review discusses on stress tolerance mechanisms in safflower. Strategies are proposed for enhancing drought and salt resistance in safflower.

Description: Grain legume production in Europe has decreased in recent years, while legume demand has rapidly increased due to growth of meat production. Therefore, Europe imports grain legumes, principally soybeans, to meet feed protein requirements. Various investigations have identified problems and benefits of local grain legume cultivation. Nevertheless, grain legume cultivation has still not increased in the last years. Studies investigating why farmers do not cultivate grain legumes are missing. Here, we surveyed the knowledge of farmers about grain legume cultivation, problems and constraints of grain legume cultivation and the barriers faced by and incentives needed by farmers. We sent a questionnaire to 1373 farmers in Luxembourg, with a response rate of 29 %. Results show that only 17 % of all the responding farmers cultivated grain legumes; 88 % of the conventional farmers did not cultivate grain legumes, while 85 % of the organic farmers did. We observed that Luxembourgish farmers feel badly informed about grain legume cultivation; organic farmers generally feel better informed than their conventional colleagues. The main barrier, named by Luxemburgish farmers to not cultivate grain legumes, is not economic issues but a lack of knowledge and extension services for these crops. Main incentives needed to start grain legume cultivation in the future are economic issues. Even though grain legume producers mentioned several negative experiences with grain legume cultivation, they are not discouraged by the poor economic conditions and appreciate the benefits of grain legume cultivation. Overall, our findings show that research results on grain legume should be better disseminated to extension services and farmers.

Description: Direct-seeded rice is a promising option because it saves water and labor, and it increases productivity. Nonetheless, few studies have evaluated the transition from traditionally transplanted rice to direct-seeded rice. Here we compared yield, water productivity, and greenhouse gas emissions of dry direct-seeded rice, wet direct-seeded rice, and transplanted rice in Central China in 2014 and 2015. We grew four rice cultivars: Huanghuazhan, LvdaoQ7, Yangliangyou6, and Yliangyou1. We measured grain yield, yield components, water consumption, water productivity, and greenhouse gas emissions. Our results show that the grain yield of wet direct-seeded rice was 10.8 % higher than that of transplanted rice, when averaged across cultivars and both years. Grain yield of dry direct-seeded rice and transplanted rice was similar. Water productivity of dry direct-seeded rice was 11.6 % higher than that of transplanted rice. Water productivity of wet direct-seeded rice was 13.4 % higher than that of transplanted rice. Global warming potential was 76.2 % lower for dry direct-seeded rice and 60.4 % lower for wet direct-seeded rice than for transplanted rice. Wet direct-seeded rice was found to be more susceptible to lodging than dry direct-seeded rice and transplanted rice. Overall, wet direct-seeded rice is the best system for Central China due to higher grain yield and water productivity and lower global warming potential. Dry direct-seeded rice may also be suitable for some regions where water is scarce for soil puddling during land preparation.

Description: 〈h3〉Abstract〈/h3〉 〈p〉Homemade botanical insecticides are widely used by subsistence and transitional farmers in low-income countries. Their use is often driven by the limited availability or cost of commercial pesticides. Homemade botanical insecticides are often recommended by agricultural extension services and some development organizations. However, this could be questioned because scientific evidence of their efficacy and safety may not be available or accessible. Although botanicals with insecticidal properties have been widely studied, a synthesis focusing specifically on homemade preparations used in realistic field or storage conditions is missing. In this paper, we review efficacy assessments of botanicals used to prepare homemade insecticides. This covers twelve botanicals recommended by national extension partners in 20 countries within the global agricultural Plantwise program. These are as follows: garlic (〈em〉Allium sativum〈/em〉), neem (〈em〉Azadirachta indica〈/em〉), chili pepper (〈em〉Capsicum〈/em〉 spp.), Siam weed (〈em〉Chromolaena odorata〈/em〉), mother of cocoa (〈em〉Gliricidia sepium〈/em〉), chinaberry (〈em〉Melia azedarach〈/em〉), moringa (〈em〉Moringa oleifera〈/em〉), tobacco (〈em〉Nicotiana tabacum〈/em〉), clove basil (〈em〉Ocimum gratissimum〈/em〉), tephrosia (〈em〉Tephrosia vogelii〈/em〉), tree marigold (〈em〉Tithonia diversifolia〈/em〉), and bitter leaf (〈em〉Vernonia amygdalina〈/em〉). This review shows that (1) all the selected botanicals contain active ingredients with insecticidal, antifeedant, or repellent properties, and (2) homemade insecticides based on all the selected botanicals have been used with some success to control pests or prevent damage, although efficacy was variable and often lower than the positive controls (synthetic pesticides). Factors affecting the efficacy of homemade botanical insecticide include variation in active ingredient content and concentration in plant material, as well as variation in the preparation process. In conclusion, there is some evidence that homemade botanical insecticides could contribute to reducing losses in food production. Since further research is needed to better understand their variable efficacy and potential health and environmental risks, those who promote the use of homemade botanical insecticides should also communicate those “unknowns” to the farmers who use such products.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉Work is a central concern for sustainable farming systems and rural communities, especially regarding specific issues of the agricultural sector, as the strong decrease in rural employment and the less attractive working conditions. Many articles covering diverse related topics have been published. However, the few studies analyzing the state of worldwide scientific research on work in agriculture give only a fragmented view, since they focus on specialized topics and disciplines. To fill this knowledge gap, the aim of this study was to review the state of research on work in agriculture addressed by the scientific literature, through a bibliometric analysis by country, institution, journal, author, and keywords. Our main finds are that (1) work in agriculture issues is divided into six main research domains: occupational health and safety, labor market and rural employment, labor and farm sustainability, work organization, agricultural policy and agrarian changes, and labor and family farms; (2) these research domains are analyzed by five scientific communities: ergonomics, agricultural economics, livestock farming systems, rural sociology, and agricultural policy; (3) the reference authors, most-cited articles, and main journals were identified for each scientific community; (4) USA, France, and China arise as leaders in the scientific landscape. We show for the first time the characteristics of the main scientific communities worldwide that have performed the most relevant research related to work in agriculture over the past 10 years. This review provides a benchmark for future research on agricultural work-related topics and encourages collaborations between researchers from different scientific communities for interdisciplinary innovation, which support sustainable working conditions in agriculture.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉Australia’s farmers are among the most efficient in the world, despite a relatively large gap between potential and achieved water-limited grain yield. With wheat yield gaps typically 〉 1.7 t/ha or 50% of the water-limited yield, it is important to investigate the degree to which this gap may be attributable to (rational) subprofit-maximising input levels in response to risk and risk aversion in many major grain-growing regions, particularly those with lower and more variable rainfall. Here, we use a set of 14 case study sites across the Australian wheatbelt to examine the risk-return profile of several agronomic management practices and show the extent to which the farmers’ risk attitude determines their decision-making. Using a novel profit-risk-utility framework that incorporates crop simulation, probability theory, finance techniques and risk-aversion analysis, we were able to better demonstrate how farmers might select practices that manage economic risk across sites ranging from low to high rainfall. Results varied with risk preference and yield potential. However, there are real opportunities to close the yield gap by adopting non-limiting or near non-limiting nitrogen fertiliser practices and controlling fallow weeds. We show for the first time that yields associated with current best practice can be surpassed for most levels of risk aversion by adopting an emergent practice of optimising the site-specific time of sowing and matching variety to time of sowing. For some sites and risk profiles, the emerging best practice package which includes additional N fertiliser is also profitable under risk. We also propose a modified integrated framework for yield gaps. Here, we distinguish allocative input constrains due to risk aversion from those due to access to resources, and we account for an innovation gap where the current agronomic frontier is shifted upwards by growers successfully, implementing new technologies that are not yet part of current best practice.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉Facing the challenge of the ecological transition of agriculture, biodiversity opens new avenues to enhance ecological interactions and reduce chemical input dependency. Designing biodiversity-based agrosystems requires an agroecological approach that combines key principles: exploring a wide range of concepts and solutions, adopting systemic reasoning, implementing a site-specific approach, developing an action-oriented process, and maintaining a continuous improvement dynamic. This type of approach has never been developed to harness mycorrhizal fungi, which are key components of soil biodiversity, because their beneficial action on crops depends on complex and underexploited ecological interactions. At present, mycorrhizae are mainly used through industrial inoculants that fit within the productionist paradigm. To shift toward agroecological approaches, we implemented a methodological framework conceived to better address the design of mycorrhiza-friendly cropping systems by sharing knowledge with farmers in four different study areas (Provence, French Guiana, Guadeloupe, and Martinique). This framework includes participative workshops, a board game, and prospective exercises to collect farmers’ proposals and the factors that prevent from implementing mycorrhiza-friendly cropping systems. We showed that 90% of the farmers proposed alternatives to industrial inoculants, 50% of them adopted systemic reasoning by combining these alternative proposals. Most farmers understood that they were all potential “mycorrhizae producers”. We showed, for the first time through on-farm experiments that valorization of indigenous mycorrhizal fungi strains using a donor plant is an effective practice to increase root colonization before planting (up to a frequency of 95% and an intensity of 32%). Considering the increasing supply of mycorrhizal inoculants and despite the uncertainty of related knowledge, we codesigned innovative practices. Learning communities (technical advisors, high school teachers, etc.) assumed responsibility for continuous improvement in knowledge and practices. Finally, beyond the issue of mycorrhizae, we showed that an agroecological approach could bring stakeholders one step further into the design of biodiversity-based agrosystems.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉Ruminant farming systems are questioned for their contribution to climate change and feed-food competition. Here, we analyse the economic and environmental performances of five sheep farming systems optimised in terms of ewe productivity and feeding costs. Systems are located in contrasting biogeographical areas along a gradient of decreasing agronomic potential from Ireland to the French Mediterranean rangelands. Applying a mechanistic model of flock and farm operation management to evaluate these five systems made it possible to highlight trade-offs between their economic performance under standardised economic conditions, environmental performances, and feed-food competition, but also discrepancies between sheep farm strategy and meat industry demands. Different management strategies resulted in ewe productivity ranging from 0.82 to 1.66 lambs ewe〈sup〉−1〈/sup〉 year〈sup〉−1〈/sup〉 between farming systems and concentrate use from 0 to 148 kg ewe〈sup〉−1〈/sup〉 year 〈sup〉−1〈/sup〉. The two systems relying the most on grassland and rangelands show the best economic and environmental performances while minimising feed-food competition. This results from a good match between animal feed requirements and forage availability; these systems, however, generate a high seasonality of production that does not meet the industry demand for a regular meat supply throughout the year. The Irish system also follows a forage autonomy strategy, but with poorer environmental and economic performance due to intensification, higher price of land, and lower meat price. Both the accelerated reproduction system with three lambing periods in two years and the organic system generate a more regular lamb supply, but require a higher level of concentrate feed, which negatively affects performances. These results highlight for the first time that optimising economic and environmental performances at farm level does not fully fit with the meat industry demand for a regular lamb meat supply throughout the year and lamb conformation. Low-productivity but fully self-sufficient fodder livestock systems can achieve excellent economic performance, but require both specific skills and marketing adequacy.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉Sustainable cropping systems that balance agricultural productivity and ecological integrity are urgently needed. Overreliance on soil tillage and herbicides to manage weeds has resulted in a number of major environmental problems including soil erosion and degradation, biodiversity loss, and water quality impairment. Combining organic farming and conservation agriculture is a viable alternative to address these challenges. In particular, mulch-based no tillage systems can be used to reduce tillage in organic production, improving soil quality while decreasing labor and fuel requirements. This technique involves planting cash crops directly into terminated cover crops that remain on soil surface and serve as mulch to prevent weeds establishment and protect soil from erosion. Despite potential benefits, adoption of organic mulch-based no tillage is limited due to challenges with cover crop termination, weed suppression, and yields. Here, we (i) review international research on organic mulch-based no tillage systems (soybean and maize), (ii) identify production issues that limit the success of this technique, and (iii) outline research priorities. As result, organic mulch-based no tillage is knowledge intensive and requires advanced planning and careful management of the cover crop. Primary challenges include timely cover crop establishment and termination, nutrient management, reduced soil temperature and moisture at planting, and achieving adequate seed-to-soil contact when planting into thick mulch on soil surface. Long-term research is needed to better understand the effects of this technique production on soil health and on the broader environmental and economic impacts. To increase adoption of organic mulch-based no tillage, future research should focus on (i) screening species and cultivars to identify cover crop and crop combinations that optimize cropping system performance and (ii) developing equipment for improving cover crop termination and seed placement. Research conducted in partnership with farmers will be valuable for developing guidelines and increasing adoption of this technique.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉Many cattle breeding programs were initiated in Africa to increase the productivity of indigenous cattle breeds. Most of these programs have failed, partly due to the lack of involvement of breeders. The present case study contributes to the understanding of such failures. The N’Dama cattle breeding program in Senegal was taken as a case study for an in-depth analysis of participation using mixed methods. Semi-structured interviews were conducted with 52 breeders: 26 who participated, 15 of whom recently resigned, and 27 who had never participated. Content and statistical analyses were conducted to evaluate the motivations of breeders and the factors influencing their participation in the breeding program. Results more particularly highlight the complexity of social issues within a breeding project, in face of classical determinants of adoption that are distance or production systems features. It pinpoints crucial levers of improvement, i.e., the management of animal property rights between the nucleus management and the participating breeders, the legitimacy of participants’ representatives in cooperatives, and the strategic mobilization of member social networks. Also, adding on previous works of the authors, this study highlights the need to take better account of the dynamics of production systems, then paying sufficient attention to the objectives, preferences, and ongoing strategies of the breeders for the future. The present study is the first to highlight the added value of mixed methods to analyze innovation adoption and participation in a livestock breeding program, taking both into account the overall innovation drivers and dynamics tied to actors’ strategies.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉Integrated weed management encourages long-term planning and targeted use of cultural strategies coherently combined at the cropping system scale. The transition towards such systems is challenged by a belief of lower productivity and higher weed pressure. Here, we hypothesize that diversifying the crop sequence and its associated weed management tools allow long-term agronomic sustainability (low herbicide use, efficient weed control, and high productivity). Four 6-year rotations with different constraints (S2: transition from reduced tillage to no-till, chemical weeding; S3: chemical weeding; S4: typical integrated weed management system; S5: mechanical weeding) were compared to a reference (S1: 3-year rotation, systematic ploughing, chemical weeding) in terms of herbicide use, weed management, and productivity over the 2000–2017 period. Weed density was measured before and after weeding. Crop and weed biomass were sampled at crop flowering. Compared to S1, herbicide use was reduced by 46, 65, and 99% in S3, S4, and S5 respectively. Herbicide use in S2 was maintained at the same level as S1 (− 9%), due to increased weed pressure and dependence to glyphosate for weed control during the fallow period of the no-till phase. Weed biomass was low across all cropping systems (0 to 5 g of dry matter m〈sup〉−2〈/sup〉) but weed dynamics were stable over the 17 years in S1 and S4 only. Compared to S1, productivity at the cropping system scale was reduced by 22% in S2 and by 33% in S3. These differences were mainly attributed to a higher proportion of crops with low intrinsic productivity in S2 and S3. Through S4’s multiperformance, we show for the first time that low herbicide use, long-term weed management, and high crop productivity can be reconciled in grain-based cropping systems provided that a diversified crop rotation integrating a diverse suite of tactics (herbicides included) is implemented.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉Weeds are one of the most important pests in agroecosystems, causing considerable economic losses on the production. The widespread use of herbicides during the last decades has led to an increased search for more environmentally sustainable methods for weed management. The manipulation of allelopathic interactions between crops and weeds, such as the introduction of an allelopathic species within a crop rotation, represents a valid alternative. In a multidisciplinary approach, we evaluated the effects resulting from three consecutive years of cultivation, in two different areas, with the three botanical varieties of 〈em〉Cynara cardunculus〈/em〉 L. (globe artichoke, cultivated and wild cardoon), compared with a classic Mediterranean wheat/faba bean rotation and an olive grove, on the quali/quantitative weed soil seed bank and the changes in the eubacterial communities. Furthermore, the in vitro antibacterial activity of aqueous, methanolic, and ethanolic leaf extracts of cultivated cardoon against three bacteria involved in the soil N-cycle was investigated. In both areas, 〈em〉C. cardunculus〈/em〉 caused a significant reduction (from − 34 to − 50%) on the amount of weed seeds in all treatments compared to controls; in some cases, a reduction of the number of weed species was observed. On one hand, the presence of cultivated cardoon had a negative influence towards 〈em〉Bacillus subtilis〈/em〉, while on the other, a positive one towards the beneficial soil bacteria 〈em〉Pseudomonas putida〈/em〉 and 〈em〉Azospirillum brasilense〈/em〉. Moreover, methanolic and ethanolic leaf extracts from cultivated cardoon showed an inhibitory activity on 〈em〉B. lichenoformis〈/em〉, while there were no negative effects on 〈em〉Rhizobium leguminosarum〈/em〉 and 〈em〉Sinorhizobium meliloti〈/em〉, two important bacteria involved in biological N〈sub〉2〈/sub〉 fixation. These results confirmed, for the first time, the field allelopathic activity of 〈em〉C. cardunculus〈/em〉 in monoculture and the possibility of introducing it within a crop rotation as an indirect method for a chemical-free weed seed bank control while respecting soil eubacterial communities.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉Maize is a globally important cereal crop and a staple in sub-Saharan Africa, where it is predominantly grown by small-scale farmers. Its production, however, is undermined by numerous herbivorous arthropods, and agrochemicals used for controlling such pests are increasingly unaffordable. Farmers therefore require cheaper, effective and environmentally sustainable pest management alternatives. This study explored the hypothesis that boosting habitat heterogeneity through organic farming and intercropping enhances arthropod predator-herbivore feeding linkages that naturally suppress herbivory across non-Bt maize fields. To test this, δ〈sup〉13〈/sup〉C and δ〈sup〉15〈/sup〉N stable isotope analyses were conducted to establish feeding pathways from maize, legume intercrops, and marginal vegetation, through arthropod herbivores and predators across 15 small-scale maize fields in western Kenya. Farming and cropping systems’ roles in trophic linkages were also assessed. Feeding connections and plant food source contributions to arthropod consumer diets were subsequently determined using Bayesian mixing models, and predator relative efficiencies also evaluated. The results showed significantly stronger predator-herbivore trophic linkages within intercropped than monoculture fields, while farming system showed no effect. Herbivores showed stronger connections to crops than to noncrops, suggesting higher vulnerability for crops. For predators, earwigs derived most basal carbon from maize; wasps and predatory beetles, from legumes; ants, from both maize and legumes; and spiders, from both crops and noncrops. Ants and earwigs are important in maize herbivore regulation, particularly for intercropping; wasps and predatory beetles for regulating legume herbivores; and spiders for whole-field herbivore regulation. Most studies have focused on single species at single-trophic levels, but here we demonstrate, for the first time in sub-Saharan Africa, application of stable isotope analyses to characterize multitrophic feeding interactions that indicate effective agronomic practices for fostering top-down arthropod herbivore suppression in non-Bt maize fields. The results are useful in prescribing field practices with low-impact habitat management for sustainable small-scale agriculture rather than pesticide-based arthropod herbivore control.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉In the European Union (EU), local production of protein crops (faba bean, field pea, lupins) is of primary interest to help farmers depend less on purchased feed, provide agronomic benefits to cropping systems, and increase the EU’s protein self-sufficiency. Nonetheless, farmers rarely grow protein crops, which currently represent less than 1% of the EU’s arable land. We assumed that exploration of farmers’ practices will bring focus on (i) their motivations for growing protein crops, so that extension programs can be improved based on these motivations, and (ii) the diversity of their crop management so that promising ones can be disseminated. In western France, a two-step survey was conducted among farmers who grew protein crops. The first step was an online survey of 127 farmers that aimed to characterize their farming systems. The second step was a face-to-face survey (69 volunteers from the 127 farmers) that aimed to collect precise data on management of protein crops. The main motivations of surveyed farmers for growing protein crops were related to (i) replacing imported soybean with farm-grown protein crops and (ii) pre-crop values of protein crops (i.e., benefits of protein crops for subsequent crops). Based on conventional farmers’ answers, we estimated a pre-crop value of 118 € ha〈sup〉−1〈/sup〉, which notably contributes to gross profit at the crop-rotation scale. Moreover, in our study, yields of protein crops did not differ significantly between conventional and organic systems. This offers an interesting opportunity for conventional systems to integrate organic practices, such as complex intercropping, to reduce variable costs (costs of seeds, pesticides, regulators, and chemical fertilizers) and increase gross profits. This study shows for the first time that, in western France, pre-crop values of protein crops and their suitability for low-input systems are undervalued and could be emphasized more strongly to encourage their adoption.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉The impact of different arable farming practices on soil erosion is only partly resolved, and the effect of conservation tillage practices in organic agriculture on sediment loss has rarely been tested in the field. This study investigated rainfall-induced interrill sediment loss in a long-term replicated arable farming system and tillage experiment (the FAST trial) with four different cropping systems: (1) organic farming with intensive tillage, (2) organic farming with reduced tillage, (3) conventional farming with intensive tillage, and (4) conventional farming with no tillage. Measurements were carried out under simulated heavy rainfall events with runoff plots in 2014 (fallow land after winter wheat) and 2017 (during maize growth). Organic farming decreased mean sediment delivery compared to conventional farming by 30% (0.54 t ha〈sup〉−1〈/sup〉 h〈sup〉−1〈/sup〉). This study demonstrated that reduced tillage in organic farming decreased sediment delivery (0.73 t ha〈sup〉−1〈/sup〉 h〈sup〉−1〈/sup〉) compared to intensively tilled organic plots (1.87 t ha〈sup〉−1〈/sup〉 h〈sup〉−1〈/sup〉) by 61%. Nevertheless, the combination of conventional farming and no tillage showed the lowest sediment delivery (0.24 t ha〈sup〉−1〈/sup〉 h〈sup〉−1〈/sup〉), whereas intensively tilled conventional plots revealed the highest delivery (3.46 t ha〈sup〉−1〈/sup〉 h〈sup〉−1〈/sup〉). Erosion rates were much higher in June during maize growth (2.92 t ha〈sup〉−1〈/sup〉 h〈sup〉−1〈/sup〉) compared to those of fallow land after winter wheat (0.23 t ha〈sup〉−1〈/sup〉 h〈sup〉−1〈/sup〉). Soil surface cover and soil organic matter were the best predictors for reduced sediment delivery, and living plant cover from weeds in reduced organic treatments appeared to protect soil surfaces better than plant residues in conventional, no-tillage plots. Soil erosion rates were significantly lower when soil cover was above 30%. In conclusion, this study demonstrates that both organic farming and conservation agriculture reduce soil losses and showed for the first time that reduced tillage practices are a major improvement in organic farming when it comes to soil erosion control.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉Cacao (〈em〉Theobroma cacao〈/em〉 L.) is a tropical perennial crop which is of great economic importance to the confectionary industry and to the economies of many countries of the humid tropics where it is grown. Some recent studies have suggested that climate change could severely impact cacao production in West Africa. It is essential to incorporate our understanding of the physiology and genetic variation within cacao germplasm when discussing the implications of climate change on cacao productivity and developing strategies for climate resilience in cacao production. Here, we review the current research on the physiological responses of cacao to various climate factors. Our main findings are as follows: (1) water limitation causes significant yield reduction in cacao, but genotypic variation in sensitivity is evident; (2) in the field, cacao experiences higher temperatures than is often reported in the literature; (3) the complexity of the cacao/shade tree interaction can lead to contradictory results; (4) elevated CO〈sub〉2〈/sub〉 may alleviate some negative effects of climate change; (5) implementation of mitigation strategies can help reduce environmental stress; and (6) significant gaps in the research need addressing to accelerate the development of climate resilience. Harnessing the significant genetic variation apparent within cacao germplasm is essential to develop modern varieties capable of high yields in non-optimal conditions. Mitigation strategies will also be essential, but to use shading to best effect shade tree selection is crucial to avoid resource competition. Cacao is often described as being sensitive to climate change, but genetic variation, adaptive responses, appropriate mitigation strategies and interactive climate effects should all be considered when predicting the future of cacao production. Incorporating these physiological responses to various environmental conditions and developing a deeper understanding of the processes underlying these responses will help to accelerate the development of a more resource use efficient tree ensuring sustainable production into the future.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉Dominant food systems are configured from the productivist paradigm, which focuses on producing large amounts of inexpensive and standardized foods. Although these food systems continue being supported worldwide, they are no longer considered fit-for-purpose as they have been proven unsustainable in environmental and social terms. A large body of scientific literature argues that a transition from the dominant food systems to alternative ones built around the wider principles of sustainable production and rural development is needed. Promoting such a sustainability transition would benefit from a diagnosis of food system types to identify those systems that may harbor promising characteristics for a transition to sustainable food systems. While research on food system transitions abounds, an operational approach to characterize the diversity of food systems taking a system perspective is still lacking. In this paper we review the literature on how transitions to sustainable food systems may play out and present a framework based on the Multi-Level Perspective on Socio-Technical Transitions, which builds upon conceptual developments from social and natural science disciplines. The objectives of the framework are to (i) characterize the diversity of existing food systems at a certain geographical scale based on a set of structural characteristics and (ii) classify the food systems in terms of their support by mainstream practices, i.e., dominant food systems connected to regimes; deviate radically from them, niche food systems such as those based on grassroots innovation; or share elements of dominant and niche food systems, i.e., hybrid food systems. An example is given of application of our framework to vegetable food systems with a focus on production, distribution, and consumption of low-or-no pesticide vegetables in Chile. Drawing on this illustrative example we reflect on usefulness, shortcomings, and further development and use of the diagnostic framework.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉The organization of work and changes in patterns of working life is of increasing concern to farmers worldwide. This creates challenges for advisors, who do not always know (i) how to recognize farmers’ or their own needs for knowledge and new approaches to farm work organization or (ii) how to assess different methods of advice to tackle this issue. How are advisors responding to this concern and what are the implications for advisory roles and the advisory situation? In this paper, we review the situation of farm work organization changes and advisory responses. We describe a conceptual framework integrating different foundations relating to work organization on farms, the farmer-advisor relationship and methods of advice. Applying this framework to farm work organization and advisory responses in Australia, Belgium, France and Uruguay, our findings are as follows: (i) the specific characteristics of work are a source of difficulties for both farmers and advisors; (ii) for the farmers, work is a very personal subject linked to identity; (iii) for the advisors, it requires different methods of advisory practice and skills; (iv) success of advisory roles in the context of farm work requires the control of various ‘role statements’; and (v) the organizational framework in which advisors carry out their activity, as well as specific training, can make it easier to identify and organize the skills.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉Achieving sustainable global food security for a rapidly growing world population is one of the greatest challenges of our time. Producing more food efficiently by closing the yield gaps is regarded as a promising solution to address this challenge without further expanding farming land. However, there is limited understanding of the causes contributing to yield gaps. The present study aimed to comprehensively examine three dimensions of the causes for the wheat yield gaps in Australia: farm management practices, farm characteristics and grower characteristics. Computer-assisted telephone interviews of 232 wheat producers from 14 contrasting local areas were conducted. The data collected on these three dimensions were used to develop a comprehensive framework to understand causes of yield gaps. Results reveal significant differences between farms with smaller yield gaps and those with greater yield gaps in relation to farming management as well as farm and grower characteristics. Findings further underline that farms with smaller yield gaps are likely to be smaller holdings growing less wheat on more favourable soil types, are more likely to apply more N fertiliser, to have a greater crop diversity, to soil-test a greater proportion of their fields, to have fewer resistant weeds, to adopt new technologies, and are less likely to grow wheat following either cereal crops or a pasture. They are more likely to use and trust a fee-for-service agronomist, and have a university education. The dynamic relationships between grower characteristics and farm management practices in causing yield gaps are further highlighted through a path analysis. This study is the first to demonstrate that yield gaps are the result of the intertwined dynamics between biophysical factors, grower socio-psychological characteristics and farm management practices. Socio-psychological factors not only directly contribute to yield gaps, but they also influence farm management practices that in turn contribute to yield gaps. Our findings suggest that, to close wheat yield gaps, it is important to develop integrated strategies that address both socio-psychological and farm management dimensions.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉Agriculture faces increasing sustainability pressures. Land intensification and degradation, energy use and inputs, complex environmental management, social issues facing farming communities and climate change are just some of the headline sustainability concerns threatening the viability of farming. Simultaneously, there is a need to increase food and fibre production and resource use efficiency. For many of these sustainability issues, increasing the number of trees planted in agricultural systems, or agroforestry, can improve the productivity and sustainability of future rural agricultural landscapes. In many parts of the world, the benefits of agroforestry remain under-realised. To understand the reasons behind this, interviews were conducted with 44 predominantly mixed enterprise farmers and farm advisors in Tasmania, Australia. Discourse analysis identified three groups of values driving perceptions and behaviours relating to agroforestry, trees as an economic proposition, trees as uneconomic and trees as essential regardless of economics. Previous work has identified many complex factors contributing to the lack of tree planting on farms including failures of past reforestation schemes, lack of awareness of the benefits of trees, perceptions of market volatility and risk, or simply a lack of time and money. This is one of the first times the underlying social norms and values creating perceptions of agroforestry have been identified. These new insights allow extension programs to tailor recommendations to identified groups based on perceptions of agroforestry. Evaluating these perceptions also allows new perspectives on opportunities for agroforestry adoption to be created, both in Tasmania and more broadly.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉The triple-bottom-line approach to sustainability in agriculture requires multi- and inter-disciplinary expertise and remains a major design and implementation challenge. Tools are needed to link extension agents, development workers, farmers, and other agriculture decision-makers to information related to practices that improve sustainability across agricultural landscapes. The digital age has brought many new cloud-based and mobile device–accessible software applications (apps) targeted at farmers and others in the agriculture sector; however, the effectiveness of these tools for advancing sustainability goals is unknown. Here, we review apps for agriculture in order to identify gaps in information provisioning and sharing for tools that connect decision-makers to knowledge in support of sustainable agricultural landscapes. The major findings are (1) Agricultural apps can be categorized as supporting regulatory compliance, equipment optimization, farming simulator games, information management, agronomic reference information, product tracking, pest identification, emissions accounting, or benchmarks for marketing claims. (2) Many apps are developed to link specific products for single solutions, such as GPS-guided crop implementation or sensors within Internet-of-things connectivity. (3) While pilots, prototypes, and case studies are available in both Apple and Android digital markets, public mobile apps to improve multidirectional agriculture knowledge exchange are limited and poorly documented. (4) There remains a need for apps emphasizing knowledge exchange and resource discovery, rather than simply information delivery, to help farmers identify evidence-based practices that improve indicators of sustainability. (5) Development of a digital decision support tool requires early and ongoing interactions with targeted end users to clarify app performance objectives and social networking preferences, ensure reliability of scientific input and business management plans, and optimize the user experience.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉Weed pressure can be high in organic and low-input farming and reduce yield and produce quality. In these systems, integrated weed management includes different agronomic practices but rarely focuses on the use of more competitive cultivars, which would reduce reliance on direct weed control methods and their detrimental effects on soil and the environment. We characterized 160 common wheat (〈em〉Triticum aestivum〈/em〉 L.) accessions cultivated in Italy since the nineteenth century for four traits linked to competitive ability against weeds (above-ground biomass before stem elongation, tillering index, plant height, and flag leaf morphology) and for two production-related traits (grain yield and thousand-kernel weight). This approach aimed to identify the most suitable combinations of competitiveness and production traits, which often show trade-offs, and led to the identification of eight accessions with reduced grain yield to plant height trade-off. We genotyped the collection with SNP markers, revealing high molecular diversity and highlighting a trend of polymorphism loss passing from heritage to modern germplasm, with the presence of unique polymorphisms in both groups. These results underline the importance of studying both heritage and elite germplasm when focusing on traits that are not targeted by formal breeding, such as the competitive ability against weeds. Marker-trait associations (MTAs) with false discovery rates (FDR) 〈 5% were detected for all traits studied, while MTAs with FDR 〈 1% were detected for plant height, biomass, grain yield, and thousand-kernel weight. We identified MTAs confirming associations already reported in the literature as well as MTAs pinpointing new genomic regions that may disclose new breeding perspectives in common wheat. This study, for the first time, shows the high potential of interdisciplinary research bridging advanced genetic studies with agroecological approaches for selecting more competitive common wheat germplasm as additional tool in more sustainable integrated weed management systems.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉Habitat management is increasingly considered as a promising approach to favor the ecosystem service of biological control by enhancing natural enemies. However, habitat management, whether at local or landscape scale, remains very uncertain for farmers. Interactions between ecological processes and agricultural practices are indeed uncertain and site-specific, which makes implementation difficult. Thus, prospecting innovations based on habitat management may benefit from integrating local stakeholders and their knowledge. Our objective is to explore with both local and scientific stakeholders how they perceive agricultural practices, ecological processes, and services related to biological pest control and habitat management. We conducted a participatory Bayesian Network modeling approach with five stakeholders in Southwest France around apple orchard cultivation. We co-constructed such Bayesian Networks based on participants’ knowledge. We explored scenarios favoring natural enemies and habitat manipulation with each participant’s Bayesian Network. We compared how different stakeholders perceive the impact of each scenario on the biological control ecosystem service. Our results indicate that a landscape with a high proportion of semi-natural habitats does not translate into significant biological control for most participants even though some stakeholders perceive a significant impact on generalist predators’ activity within orchards. For these local stakeholders, habitat management at the orchard level such as inter-row vegetation seems currently more promising than at the landscape scale. Here, we show for the first time that the use of Bayesian modeling in a participatory manner can give precious insights into the most promising perspectives on habitat management at different scales. These different local perspectives suggest in particular that further dialogue between ecologists and local stakeholders should be sought about inter-row habitat management as the most promising practice to foster biological pest control and other ecosystem services.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉Cover crops provide many ecosystem services, such as soil protection, nitrate pollution of water mitigation, and green manure effects. However, the impact of cover crops on soil water balance is poorly studied, despite its potential impact on groundwater recharge. Some studies reported a reduction of the water drainage due to an increase of the evapotranspiration by plant cover transpiration. However, there is no real consensus on the intensity of this phenomenon, which highlights the importance to quantify the impact of cover crops on drainage compared to that of bare soil. We performed a meta-analysis of published papers presenting studies on the impact of cover crops on drainage compared to that of bare soil under temperate climates. Of the 436 papers identified, 28 of them were included in the analysis based on criteria required for performing a relevant meta-analysis. The originality of our study lies in two following results: (1) the quantification of drainage reduction with cover crops by a mean effect size of 27 mm compared to that of bare soil and (2) within the large variability of soils, climates, and cropping systems, no main determining factor was found significant to explain the variability of water drainage reduction. The cover crops provide a service of nitrate pollution mitigation, but the drainage reduction could be considered as a disservice, because they can lead to a reduction in groundwater recharge due to a higher evapotranspiration in comparison to bare soil. This highlights the need of research for optimizing trade-offs between services and disservices of cover crops for water balance.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉An increasing number of vineyards are converting to organic farming due to concerns about the environmental impacts of agriculture. How difficult this shift is depends on farms’ biophysical and economic situations as well as on their specific dynamics. Methods to analyze, assess, and support transition strategies are needed. In this context, the hypothesis can be made that the efficiency-substitution-redesign approach, which is used for describing the level, intensity, and speed of changes made by vineyards, could be used to classify transition strategies. On-farm interviews and surveys were conducted at vineyards in conversion to organic farming in two French winegrowing regions: Languedoc and Bordeaux. The agronomic changes made to various grape production technical operations during the conversion period were described and assessed by using the efficiency-substitution-redesign approach. Potential economic consequences of conversion were measured by looking at farms’ accounting records. Considering the high number of variables taken into account in the detailed analysis of each operation for the conversion to organic farming, the efficiency-substitution-redesign approach was successfully used to classify transition strategies according to the type of changes made. The results showed that change intensity varied between farms with no clear correlation between the type of changes and economic consequences. Farm trajectories were then correlated to the speed and intensity of changes with quantitative transition indicators. Here, a quantitative application of the efficiency-substitution-redesign approach was used for the first time to assess and classify organic farming conversion strategies according to a scale of change intensity and speed of changes. These results are essential to enhance understanding of what happens during conversion to organic farming and to better support winegrowers’ trajectories.〈/p〉

Description: 〈h3〉Abstract〈/h3〉 〈p〉Once again, agricultural mechanization is top on the policy, research, and development agendas in sub-Saharan Africa. However, whether labor is limiting in this region—and mechanization is in demand—remains debated. The hypothesis of this study is that labor is a major limiting factor to the productivity of most farming systems in Africa. We used farm-level data (including detailed labor data) from eight sites dominated by smallholder agriculture and spanning four countries in Eastern and Southern Africa, and analyzed this unique dataset using multivariate methods (generalized linear models, boundary line analysis, and binary classification and regression trees). Labor and/or other sources of farm power (draught power or tractor power) were found to limit land productivity in all study sites. We also found that the overall contribution of female labor to farming was much lower than commonly stated—between 7 and 35%—and that the labor intensity experienced by women in agriculture was dependent to a large degree on men’s tasks. Our results reveal a much higher demand for mechanization than previously found by macroeconomic analyses, and point to a problem of access rather than demand. Our results also add to recent evidence debunking the persistent myth that women provide the bulk of the farming labor, and demonstrate that reducing labor intensity experienced by women in farming depends to a large degree upon understanding labor intensity experienced by men, rather than poorly founded generalizations about how women are overworked. This is the first time farm-level data containing detailed labor assessment and spanning four countries are used to assess mechanization demand in Africa. This paper also plays a pioneering role in debunking a number of myths related to labor in African smallholder agriculture, with implications for the mechanization agenda of the region.〈/p〉

Description: The nitrogen (N) dilution curve is a useful tool for farmers to assess the effectiveness of fertilizer application. The N dilution curve describes the decrease in plant N as biomass increases. This concept has not yet been tested for its applicability and robustness under different cutting regimes in grasslands. We conducted a principal components analysis on biomass yield and N concentration data to discern relationships among experimental, climatic, and management factors. Next, two N dilution curve parameters were calibrated for different cutting frequencies. We compared N uptake using four different methods utilizing calibrated N dilution curves, a reference curve, and different cutting regimes representing different physiological ages of the crops at cutting. Our results show that excluding cutting frequency information overestimates values of N uptake. Calibration of the N dilution curve according to cutting frequency improves N uptake estimates relative to observed values. Therefore, N uptake is better estimated using both the N dilution curve and the cutting regime information.

Description: Industrial agriculture is not efficient anymore due in particular to the use of nonrenewable energy such as fossil fuels. Organic agriculture is an alternative system that aims to reduce the consumption of fossil fuels, pesticides, and mineral fertilizers. Animal–crop systems present potential mutual benefits, but such systems have been rarely studied quantitatively. Here, we compare energy inputs and outputs of organic rice–duck farming with conventional rice production in Mazandaran province, Iran. Our results show that the global energy input of organic rice–duck, 79,307 MJ ha −1 , is lower than that of conventional rice, 94,377 MJ ha −1 . On the contrary, the energy output of organic rice–duck, 117,325 MJ ha −1 , is higher than that of conventional rice, 111,914 MJ ha −1 . The most used energy was fuel, amounting to 40 % of total energy for organic rice–duck and 33 % for conventional rice. Then, machinery consumed 25 % of total energy for organic rice–duck and 20 % for conventional rice. Then, fertilizers consumed 20 % of total energy in the form of organic fertilizers for organic rice–duck versus 16 % in the form of mineral fertilizers for conventional rice. Overall, our findings show that organic rice–duck farming has more energy efficiency than conventional rice farming.

Description: Urban agriculture may solve issues of feeding urban populations. In China, for example, densely packed mega cities will continue to expand in number and size, necessitating increasing food miles. Interestingly, it has been estimated that the total rooftop space in China is about 1 million hectares, some of which can be converted for rooftop farming. Yet, despite some favorable reports on urban farming, the Chinese commercial sector has shown little interest. This may be explained by the dearth of data comparing urban and conventional farming. Therefore, we present here a feasibility study of hydroponically grown vegetables in a rooftop screen house in Guangzhou, China. From December, 2012 to May, 2014, we tested the production of seven leafy vegetables that are easily perishable and are not well suited to long-distance transport. We calculated the production cost and measured biochemical parameters. Results show that levels of vitamin C, potassium, calcium, magnesium, iron, zinc, and crude fiber were comparable to market counterparts. None of the roof hydroponic vegetables exceeded the maximum residue limit for lead, arsenic, cadmium, chromium, mercury, or nitrate. In contrast, 5 of 98 market vegetables were contaminated by exceeding the maximum residue limit for lead. Similarly 3 were contaminated for arsenic, 23 for nitrate, and 2 for organophosphate or carbamate insecticide. Compared to high-end vegetables sold on the market, rooftop-grown vegetables were competitive in cost and quality. Given that many countries have limited arable land to feed a large population, the widespread adoption of rooftop hydroponics could help expand the total area available for food production as well as meet the rising demand for safe high-quality vegetables.

Description: Agroforestry systems usually include a high density and diversity of shade trees. Such systems often have a large diversity of fauna and flora and provide local and regional ecosystem services. Shade trees are, however, being removed to increase crop production in many tropical regions. There is little knowledge on the effect of shade trees on crop production in the context of trade-offs with other management practices. We therefore compared the benefits of exotic versus native shade trees on coffee production. We evaluated the importance of shade tree management for crop production in the context of management practices. Management practices included fertilization, liming, coffee pruning, weeding, and irrigation in 113 coffee agroforests in Kodagu, India, over a wide range of shade tree density, tree species diversity, and shade cover. We studied, in particular, Grevillea and non- Grevillea shade trees, the latter including mostly native tree species. Results show that a rise of 100 non- Grevillea shade tree per hectare increased production of berries by 5.6 % and larger beans by 6.25 %. Irrigation and liming increased berry production respectively by 16 and 20 %. These management interventions are likely to offset the relatively small negative effect of reducing shade density of non- Grevillea trees on coffee production. Recommendations based on an understanding of shade tree management alone can be misleading with regard to crop production.

Description: Agricultural production involves the scaling of agricultural innovations such as disease-resistant and drought-tolerant maize varieties, zero-tillage techniques, permaculture cultivation practices based on perennial crops and automated milking systems. Scaling agricultural innovations should take into account complex interactions between biophysical, social, economic and institutional factors. Actual methods of scaling are rather empirical and based on the premise of ‘find out what works in one place and do more of the same, in another place’. These methods thus do not sufficiently take into account complex realities beyond the concepts of innovation transfer, dissemination, diffusion and adoption. As a consequence, scaling initiatives often do not produce the desired effect. They may produce undesirable effects in the form of negative spill-overs or unanticipated side effects such as environmental degradation, bad labour conditions of farm workers and loss of control of farming communities over access to genetic resources. Therefore, here, we conceptualise scaling processes as an integral part of a systemic approach to innovation, to anticipate on the possible consequences of scaling efforts. We propose a method that connects the heuristic framework of the multi-level perspective on socio-technical transitions (MLP) to a philosophical ‘modal aspects’ framework, with the objective of elucidating the connectedness between technologies, processes and practices. The resultant framework, the PRactice-Oriented Multi-level perspective on Innovation and Scaling (PROMIS), can inform research and policymakers on the complex dynamics involved in scaling. This is illustrated in relation to three cases in which the framework was applied: scaling agro-ecological practices in Nicaragua, farmer field schools on cocoa cultivation in Cameroon and ‘green rubber’ cultivation in Southwest China.

Description: There is an increase of biosecurity threats in agriculture because greater urbanisation and movement of humans means that pests migrate more easily than ever before. Poor management of biosecurity risks can lead to threats to human health, animal health and food or material production. Quality assurance programs and guidelines for best management practices exist in the plant and animal farming sector. However, there is scarce knowledge on individual decision-making relevant to biosecurity, motivation to implement protective behaviours and human adherence to biosecurity practices. Indeed, people have often long-term habits that are resistant to behaviour change initiatives. These conservative habits limit the effectiveness of risk management interventions and attention to new information that contradicts existing attitudes and beliefs. This paper reviews the potential influences of psychological, social and cognitive factors on biosecurity-related behaviour and management practices. The major aspects covered in this review are as follows: (1) underlying attitudes to biosecurity risk and perceived vulnerability to a biosecurity threat, (2) the influence of social incentives and social norms on individual behaviour, (3) motivational drivers and the notion of threat perception in engaging in protective behaviour, (4) consideration of emotional and cognitive biases in assessing risk and (5) the influence of pre-existing antecedents of decision-making beyond personal factors, such as context and policy within which decisions must be made. This review makes the critical point that human adoption and adherence to biosecurity practices is influenced by psychosocial factors and is an area of urgent research and policy consideration. An exploratory model is presented for future research and on-the-ground considerations, incorporating psychosocial influences on decision-making and potential mediating factors.

Description: Soil mineral depletion is a major issue due mainly to soil erosion and nutrient leaching. The addition of biochar is a solution because biochar has been shown to improve soil fertility, to promote plant growth, to increase crop yield, and to reduce contaminations. We review here biochar potential to improve soil fertility. The main properties of biochar are the following: high surface area with many functional groups, high nutrient content, and slow-release fertilizer. We discuss the influence of feedstock, pyrolysis temperature, pH, application rates, and soil types. We review the mechanisms ruling the adsorption of nutrients by biochar.

Description: Mineral nitrogen fertilization has improved crop yield over the last century but has also caused air and water pollution. Reduction of nitrogen inputs and maintaining high yields are therefore essential to ensure a more sustainable agriculture. Improving the nitrogen use efficiency (NUE) of crops is therefore needed. Rapeseed, Brassica napus , depends on nitrogen fertilization due to its low NUE, with the ratio of plant nitrogen content to nitrogen supplied often not exceeding 60 %. Here, we review the major phenotypic traits associated with NUE in B. napus , with special emphasis on winter oilseed rape. We discuss the genetic diversity available and potential breeding strategies. The major points are the following: (1) rapeseed seed yield elaboration is complex, with overlapping phases of nitrogen uptake and remobilization during the crop cycle; (2) traits related to nitrogen uptake, such as root length and the amount of nitrogen absorbed after flowering, and traits related to nitrogen remobilization, such as the “stay-green” phenotype, have been identified as possible levers to improve NUE in rapeseed; (3) a substantial body of studies investigating the genetic control of NUE traits have already published and potential candidate genes identified; and (4) rapeseed genetic diversity may be enriched by exploiting interpopulation genetic variation and the closely related gene pools of Brassica rapa and Brassica oleracea .

Description: Arbuscular mycorrhizal fungi are root symbionts that play a key role in crop growth. A systematic quantitative analysis of the response of crops to arbuscular mycorrhizal inoculation, however, remains to be done. Additionally, little is known regarding the role of mycorrhizal specificity and the diversity of the inoculum on crop growth. Therefore, we collected data from 115 inoculation studies, including 435 experiments. We then used meta-analysis to examine the effect of crop identity, arbuscular mycorrhizal fungus identity, and mycorrhizal diversity on crop biomass increase, following inoculation. Our results show that total crop biomass was on average 34.9 % higher in inoculated versus non-inoculated plants. We found that specific combinations of arbuscular mycorrhizal fungus genera and host plant families were more beneficial for growth promotion as compared to other combinations. Moreover, a single-species inoculum increased crop growth response on average by 41.2 % compared to a multi-species inoculum. Overall, our findings show that a broad range of crops highly benefit from the inoculation with arbuscular mycorrhizal fungi. They also strongly suggest that selecting specific arbuscular mycorrhizal taxa for specific crops is the most promising approach to enhance crop growth. There is no “one-size-fits-all” arbuscular mycorrhizal fungus. Finally, and at least in stable and controlled environments, inoculation with a single arbuscular mycorrhizal species is more effective, compared to inoculation with a mixture of different arbuscular mycorrhizal taxa. This may be explained by fungi superior in extraradical growth, but less beneficial to the host, that outcompete the more mutualistic fungi. Therefore, it may be beneficial to maintain a high dominance of one beneficial arbuscular mycorrhizal taxon in simplified agricultural systems.

Description: Mycotoxins contaminate maize and thus pose a serious economic and health risk. Despite the prevalence of mycotoxins in maize and other crops, the agricultural management system has not yet been fully implemented in China. Thereby, there is an urgent need to implement management programs to control mycotoxin contamination in maize and maize-based feed. Here, we conducted a survey on the traditional maize production and feed processing practices in the Hebei province. We analyzed the factors of fungal infection and subsequent mycotoxin contamination in maize and feed supply chain and management systems. Our results show that the stored maize samples from local feed mills were heavily contaminated with fumonisin, at 9638 μg/kg on the average, and deoxynivalenol, at 996.3 μg/kg on the average. We also found that more than 75.0 % of the farmers followed good agricultural practices, whereas only 38.1 % of the farmers cared for storage conditions. The main factors for mycotoxin contamination included less strict receiving and inspection criteria, inappropriate storage conditions, and poor processing practices. The critical control points were feed mill receiving, storage, and feed processing. Visual quality, moisture contents, and mycotoxin levels in maize and feed were used as monitoring parameters at critical control points. This is the first study to thoroughly explore traditional maize and feed manufacturing practices adopted by farmers.

Description: Paradoxically, the number of crop–livestock farms is declining across Europe, despite the fact that crop-livestock farms are theoretically optimal to improve the sustainability of agriculture. To solve this issue, crop–livestock integration may be organized beyond the farm level. For instance, local groups of farmers can negotiate land-use allocation patterns and exchange materials such as manure, grain, and straw. Development of such a collective agricultural system raises questions, rarely documented in the literature, about how to integrate crops and livestock among farms, and the consequences, impacts, and conditions of integrating them. Here, we review the different forms of crop–livestock integration beyond the farm level, their potential benefits, and the features of decision support systems (DSS) needed for the integration process. We identify three forms of crop–livestock integration beyond the farm level: local coexistence, complementarity, and synergy, each with increasingly stronger temporal, spatial, and organizational coordination among farms. We claim that the forms of integration implemented define the nature, area, and spatial configuration of crops, grasslands, and animals in farms and landscapes. In turn, these configurations influence the provision of ecosystem services. For instance, we show that the synergy form of integration promotes soil fertility, erosion control, and field-level biological regulation services through organizational coordination among farmers and spatiotemporal integration between crops, grasslands, and animals. We found that social benefits of the synergy form of integration include collective empowerment of farmers. We claim that design of the complementarity and synergy forms of crop–livestock integration can best be supported by collective participatory workshops involving farmers, agricultural consultants, and researchers. In these workshops, spatialized simulation modeling of crop–livestock integration among farms is the basis for achieving the upscaling process involved in integrating beyond the farm level. Facilitators of these workshops have to pay attention to the consequences on governance and equity issues within farmers groups.

Description: The industrialization of agriculture has led to lower efficiency and greater dependence on non-renewable energy. Organic agriculture and traditional agriculture are thus potential alternatives. Cacao is a major crop in Ecuador. However, information on the energy efficiency and economic performance of Ecuadorian cacao in relation to the production management system is rare and basically inexistent in the case of organic management. Therefore, we studied here the energy and economic performance of the cacao production in the province of Guayas, Ecuador. Four types of management were identified in the province: traditional, semi-intensive, technified, and organic. On the basis of primary data, input-output and energy efficiency were estimated, with special attention given to the use of non-renewable energy and the monetary profitability of each management system. The total energy inputs of the different forms of management have been estimated at 3.04 for traditional, 12.47 for semi-intensive, 24.53 for technified, and 9.77 GJ ha −1 for organic. Irrigation, fertilization, and crop protection are the most important inputs for all four types of management, ranging between 85.7 and 97.7 %. The non-renewable external energy return on the investment (EROI) has been estimated at 1:2.93 for traditional, 1:1.85 for semi-intensive, 1:1.47 for technified, and 1:3.07 for organic. The different forms of management earned a net margin of 484 for traditional, 1051 for semi-intensive, 2323 for technified, and $1565 ha −1 for organic. Our findings show that the intensification of cacao production increases the net margin per hectare in relation to traditional cacao production, while it significantly reduces its non-renewable external EROI. Well-managed organic farms allow improving non-renewable external EROI by comparison with technified or semi-intensive management strategies, and it also improves the economic performance in relation to semi-intensive systems.

Description: World population is projected to reach over nine billion by the year 2050, and ensuring food security while mitigating environmental impacts represents a major agricultural challenge. Thus, higher productivity must be reached through sustainable production by taking into account climate change, resources rarefaction like phosphorus and water, and losses of fertile lands. Enhancing crop diversity is increasingly recognized as a crucial lever for sustainable agro-ecological development. Growing legumes, a major biological nitrogen source, is also a powerful option to reduce synthetic nitrogen fertilizers use and associated fossil energy consumption. Organic farming, which does not allow the use of chemical, is also regarded as one prototype to enhance the sustainability of modern agriculture while decreasing environmental impacts. Here, we review the potential advantages of eco-functional intensification in organic farming by intercropping cereal and grain legume species sown and harvested together. Our review is based on a literature analysis reinforced with integration of an original dataset of 58 field experiments conducted since 2001 in contrasted pedo-climatic European conditions in order to generalize the findings and draw up common guidelines. The major points are that intercropping lead to: (i) higher and more stable grain yield than the mean sole crops (0.33 versus 0.27 kg m −2 ), (ii) higher cereal protein concentration than in sole crop (11.1 versus 9.8 %), (iii) higher and more stable gross margin than the mean sole crops (702 versus 577 € ha −1 ) and (iv) improved use of abiotic resources according to species complementarities for light interception and use of both soil mineral nitrogen and atmospheric N 2 . Intercropping is particularly suited for low-nitrogen availability systems but further mechanistic understanding is required to propose generic crop management procedures. Also, development of this practice must be achieved with the collaboration of value chain actors such as breeders to select cultivars suited to intercropping.

Description: Diverse, severe, and location-specific impacts on agricultural production are anticipated with climate change. The last IPCC report indicates that the rise of CO 2 and associated “greenhouse” gases could lead to a 1.4 to 5.8 °C increase in global surface temperatures, with subsequent consequences on precipitation frequency and amounts. Temperature and water availability remain key factors in determining crop growth and productivity; predicted changes in these factors will lead to reduced crop yields. Climate-induced changes in insect pest, pathogen and weed population dynamics and invasiveness could compound such effects. Undoubtedly, climate- and weather-induced instability will affect levels of and access to food supply, altering social and economic stability and regional competiveness. Adaptation is considered a key factor that will shape the future severity of climate change impacts on food production. Changes that will not radically modify the monoculture nature of dominant agroecosystems may moderate negative impacts temporarily. The biggest and most durable benefits will likely result from more radical agroecological measures that will strengthen the resilience of farmers and rural communities, such as diversification of agroecosytems in the form of polycultures, agroforestry systems, and crop-livestock mixed systems accompanied by organic soil management, water conservation and harvesting, and general enhancement of agrobiodiversity. Traditional farming systems are repositories of a wealth of principles and measures that can help modern agricultural systems become more resilient to climatic extremes. Many of these agroecological strategies that reduce vulnerabilities to climate variability include crop diversification, maintaining local genetic diversity, animal integration, soil organic management, water conservation and harvesting, etc. Understanding the agroecological features that underlie the resilience of traditional agroecosystems is an urgent matter, as they can serve as the foundation for the design of adapted agricultural systems. Observations of agricultural performance after extreme climatic events (hurricanes and droughts) in the last two decades have revealed that resiliency to climate disasters is closely linked to farms with increased levels of biodiversity. Field surveys and results reported in the literature suggest that agroecosystems are more resilient when inserted in a complex landscape matrix, featuring adapted local germplasm deployed in diversified cropping systems managed with organic matter rich soils and water conservation-harvesting techniques. The identification of systems that have withstood climatic events recently or in the past and understanding the agroecological features of such systems that allowed them to resist and/or recover from extreme events is of increased urgency, as the derived resiliency principles and practices that underlie successful farms can be disseminated to thousands of farmers via Campesino a Campesino networks to scale up agroecological practices that enhance the resiliency of agroecosystems. The effective diffusion of agroecological technologies will largely determine how well and how fast farmers adapt to climate change.

Description: Agricultural landscapes presently cover about 46 % of earth terrestrial surface. This cultivated area is decreasing, whereas the global food demand is projected to increase up to 70 % in 2050. The intensification of agriculture is not a solution to this food issue because intensive agriculture has often resulted in pollution and loss of biodiversity. On the other hand, mechanistic models with optimization algorithms can be used to design alternative land uses for sustainable agriculture. Here, we present a review of metaheuristics for land use optimization reported in 50 articles including 38 case studies carried out in 16 countries. Our main conclusions are: 1) the success of metaheuristics is problem-dependent. In general, metaheuristics enable search to escape from local optima and find a good global approximation solution. 2) The choice of a given metaheuristic for solving a given problem seems to be driven by its historical use in a research team and by its popularity outside the metaheuristics research community, rather than by the characteristics of the problems to be solved and by the latest results from the metaheuristics research community. 3) Stakeholders of land use are increasingly involved at different levels of the land use optimization procedure and multi-actors decision-making methods are necessary to find trade-offs between their competing interests. 4) A future challenge is the use of parallelization techniques along with the hybridization of different metaheuristics or of metaheuristics with other optimization methods.

Description: The overuse of pesticides leads to contamination of water and food. Therefore, there is a need for tools and strategies to optimize pesticide application. Here we present SnapCard, a user-friendly and freely available decision support tool for farmers and agricultural consultants, available at snapcard.agric.wa.gov.au. SnapCard allows to predict, measure, and archive pesticide spray coverage quantified from water-sensitive spray cards. Variables include spray settings such as nozzle orifice size, sprayer speed, water carrier rate and adjuvant, and weather variables such as barometric pressure, relative humidity, temperature, and wind speed at ground level. We use separate regression models for four nozzles types. Our results showed that there are strong and positive correlations between water carrier rate and spray coverage for all four nozzle types. Moreover, sprayer speed is highly negatively correlated with obtained spray coverage. In addition, there is no consistent effect of either nozzle type or use of a particular adjuvant, across water carrier intervals. We conclude that varying combinations of spray settings and weather conditions caused marked ranges of spray coverages among the four nozzle types, thus highlighting the importance of selecting the right nozzle orifice size and type. We demonstrate that realistic scenarios of environmental conditions and spray settings can lead to predictions of very low spray coverage with at least one of the four nozzle types. We discuss how the novel and freely available smartphone app, SnapCard, can be used to optimize spray coverage, reduce spray drift, and minimize the risk of resistance development in target pest populations.

Description: Grassland covers about one quarter of the Earth’s land area and is currently estimated to contribute to the livelihoods of over 800 million people. Grassland provides ecosystem goods and services, mainly through the provisioning of milk and meat. Therefore, the proper use of grasslands will be essential for feeding the nine billion people that will inhabit planet Earth by 2050. In the context of a changing climate, we should better understand the interactions of environment, management and grass crop at individual, community and ecosystem levels. Functional ecology focuses on the roles and functions that species play in the community or ecosystem in which they occur. Functional ecology thus aims to understand how plant species adapt to environmental conditions and how management can alter this adaptation. Here, we review the latest advances in plant functional traits research and on species strategies to the main environmental factors occurring in grassland ecosystems: nutrient availability, grazing, cutting and shading. Functional ecology also provides a framework to better understand how species strategies interact with the species composition at the community level. Therefore, the literature on community assembling theories in relation to ecosystem processes most relevant to grassland management and services is also reviewed. Finally, future research questions and some new orientations for grassland experts are offered in order to meet the challenge of maintaining productivity and preservation of these semi-natural environments in the face of global change.

Description: One of the challenges of organic crop certification is the efficient targeting of the relatively small percentage of risk-sensitive fields that have to be controlled during the regulatory annual in situ inspection. A previous study carried out on wheat and maize in Germany has shown that organic and non-organic crops can be efficiently distinguished by remote sensing. That study pointed to the possibility that these techniques could be used for helping organic crop certification bodies to better target risk-sensitive fields. This study is a first adaptation of that research on organic cotton in southwestern Burkina Faso, West Africa. This study assumed that organic and non-organic cotton, primarily because of their different approaches to fertilization and pest control, would result in bio-chemico-physical differences measurable by both in situ and remote sensing indicators. This study included 100 cotton fields, of which 50 were organic, 28 conventional, and 22 genetically modified. In situ indicators were derived from chlorophyll content, canopy cover, height, and spatial heterogeneity measurements. Remote sensing spectral and spatial heterogeneity indicators were derived from two SPOT 5 satellite images. Discriminant models were then computed. The results show statistically highly significant differences between organic and non-organic cotton fields for both in situ and satellite indicators, using univariate and multivariate linear models, with up to 86 % discrimination performance. This is the first time that the efficiency of using remote sensing to discriminate between organic and non-organic crops is evaluated in a developing country, particularly for cotton, with good discrimination being achieved. Pending further validation, it therefore seems that remote sensing could be used to enhance organic cotton certification in West Africa by enabling more efficient targeting of suspect fields and consequently could contribute to a better development of this sector.

Description: New agricultural systems are required to satisfy societal expectations such as higher quantity and quality of agricultural products, reducing environmental impacts, and more jobs. However, identifying and implementing more suitable agricultural systems is difficult due to conflicting objectives and to the wide diversity of scientific disciplines required to solve agricultural issues. Therefore, designing models to assess the sustainability of agricultural systems requires multi-criteria decision aid methods. The French agronomist community has recently developed 11 hierarchical and qualitative models to assess sustainability using the DEXi decision aid software. Here, we give guidelines to help designers to build their own specific models. First, we present the principles and applications of the DEXi software. Then, we provide guidance on the following steps of model designing: (1) initial analysis and planning of the design process, (2) selection and hierarchy of sustainability criteria, (3) indicator selection and building, (4) parameterization, (5) evaluation, and (6) model dissemination and uses. We then discuss advantages and drawbacks of this kind of modeling formalism, the role of a participatory approach, and the main properties to consider during the design process.

Description: Food production has to be significantly increased in order to feed the fast growing global population estimated to be 9.1 billion by 2050. The Green Revolution and the development of advanced plant breeding tools have led to a significant increase in agricultural production since the 1960s. However, hundreds of millions of humans are still undernourished, while the area of total arable land is close to its maximum utilization and may even decrease due to climate change, urbanization, and pollution. All these issues necessitate a second Green Revolution, in which biotechnological engineering of economically and nutritionally important traits should be critically and carefully considered. Since the early 1990s, possible applications of plastid transformation in higher plants have been constantly developed. These represent viable alternatives to existing nuclear transgenic technologies, especially due to the better transgene containment of transplastomic plants. Here, we present an overview of plastid engineering techniques and their applications to improve crop quality and productivity under adverse growth conditions. These applications include (1) transplastomic plants producing insecticidal, antibacterial, and antifungal compounds. These plants are therefore resistant to pests and require less pesticides. (2) Transplastomic plants resistant to cold, drought, salt, chemical, and oxidative stress. Some pollution tolerant plants could even be used for phytoremediation. (3) Transplastomic plants having higher productivity as a result of improved photosynthesis. (4) Transplastomic plants with enhanced mineral, micronutrient, and macronutrient contents. We also evaluate field trials, biosafety issues, and public concerns on transplastomic plants. Nevertheless, the transplastomic technology is still unavailable for most staple crops, including cereals. Transplastomic plants have not been commercialized so far, but if this crop limitation were overcome, they could contribute to sustainable development in agriculture.

Description: Intensive agriculture has led to several drawbacks such as biodiversity loss, climate change, erosion, and pollution of air and water. A potential solution is to implement management practices that increase the level of provision of ecosystem services such as soil fertility and biological regulation. There is a lot of literature on the principles of agroecology. However, there is a gap of knowledge between agroecological principles and practical applications. Therefore, we review here agroecological and management sciences to identify two facts that explain the lack of practical applications: (1) the occurrence of high uncertainties about relations between agricultural practices, ecological processes, and ecosystem services, and (2) the site-specific character of agroecological practices required to deliver expected ecosystem services. We also show that an adaptive-management approach, focusing on planning and monitoring, can serve as a framework for developing and implementing learning tools tailored for biodiversity-based agriculture. Among the current learning tools developed by researchers, we identify two main types of emergent support tools likely to help design diversified farming systems and landscapes: (1) knowledge bases containing scientific supports and experiential knowledge and (2) model-based games. These tools have to be coupled with well-tailored field or management indicators that allow monitoring effects of practices on biodiversity and ecosystem services. Finally, we propose a research agenda that requires bringing together contributions from agricultural, ecological, management, and knowledge management sciences, and asserts that researchers have to take the position of “integration and implementation sciences.”

Description: Industrial fertilization with an excess of mineral fertilizer leads to water pollution and global warming. For instance, high mineral fertilization rates in coffee plantations of Ecuador result in N losses, such as emissions of N 2 O, a greenhouse gas to the atmosphere. Therefore, we conducted here field experiments to optimize fertilization. We studied the effects of mineral fertilizers on soil fertility, N 2 O emissions, productivity, and profitability of monoculture coffee systems in Loja, Ecuador. During 2 years, treatments on plots of Coffea arabica included (1) low fertilization with 70 N, 22 P, and 31 K kg/ha/year first year and then 200 N, 65 P, and 62 K second year; (2) medium fertilization with 150 N, 44 P, and 62 K first year and then 300 N, 87 P, and 125 K second year; (3) high fertilization with 225 N, 65 P, and 93 K and then 400 N, 109 P, and 187 K second year; and (4) control plots without fertilizers. Results showed that, although medium-high fertilization rates recommended by experts gave high coffee yields and income, such treatments produced high N 2 O emissions and thus led to low production/N 2 O emissions ratios of 208 for medium fertilization, and of 188 for high fertilization. Low fertilization gave a high production/N 2 O ratio of 603, and an income of 7606 USD/ha higher than control, of 3524 USD/ha. Our findings demonstrate that rates based on expert recommendations from local extension services and usually applied by Ecuadorian coffee growers, such as our medium rate, fail to achieve a sustainable production. The application of approximately half the expert recommended rates, such as our low treatment, could allow an environmental and economic sustainability in monoculture coffee plantations of Ecuador.

Description: Spodoptera frugiperda is a major pest causing maize yield loss in Brazil. There is therefore a need for control methods, notably for organic farming because classical pesticides are not allowed. A potential solution for organic maize is to apply the biological control agent Trichogramma pretiosum to reduce S. frugiperda populations. Here, we tested the application of one, two, or three releases of T. pretiosum . We measured plant damage ratings, egg masses parasitized, and grain yield. Results show that 79.2 % of egg masses were parasited. Maize yields for parasited plots increased of 701 kg/ha versus control plots. This result equals a 19.4 % gain of productivity and US$96.5 gain per hectare. Therefore, biological control with egg parasitoids is a promising alternative to control S. frugiperda in organic maize.

Description: Phthalic acid esters have been used as plasticizers in numerous products and classified as endocrine-disrupting compounds. As China is one of the largest consumers of phthalic acid esters, some human activities may lead to the accumulation of phthalic acid esters in soil and result in contamination. Therefore, it is necessary for us to understand the current contamination status and to identify appropriate remediation technologies. Here, we reviewed the potential sources, distribution, and contamination status of phthalic acid esters in soil. We then described the ecological effect and human risk of phthalic acid esters and finally provided technologies to remediate phthalic acid esters. We found that (1) the application of plastic agricultural films, municipal biosolids, agricultural chemicals, and wastewater irrigation have been identified as the main sources for phthalic acid ester contamination in agricultural soil; (2) the distribution of phthalic acid esters in soils is determined by factors such as anthropogenic behaviors, soil type, properties of phthalic acid esters, seasonal variation, etc.; (3) the concentrations of phthalic acid esters in soil in most regions of China are exceeding the recommended values of soil cleanup guidelines used by the US Environmental Protection Agency (US EPA), causing phthalic acid ester in soils to contaminate vegetables; (4) phthalic acid esters are toxic to soil microbes and enzymes; and (5) phthalic acid ester-contaminated soil can be remedied by degradation, phytoremediation, and adsorption.

Description: Maize is grown under a wide spectrum of soil and climatic conditions. Maize is moderately sensitive to salt stress; therefore, soil salinity is a serious threat to its production worldwide. Understanding maize response to salt stress and resistance mechanisms and overviewing management options may help to devise strategies for improved maize performance in saline environments. Here, we reviewed the effects, resistance mechanisms, and management of salt stress in maize. Our main conclusions are as follows: (1) germination and stand establishment are more sensitive to salt stress than later developmental stages. (2) High rhizosphere sodium and chloride decrease plant uptake of nitrogen, potassium, calcium, magnesium, and iron. (3) Reduced grain weight and number are responsible for low grain yield in maize under salt stress. Sink limitations and reduced acid invertase activity in developing grains is responsible for poor kernel setting under salt stress. (4) Exclusion of excessive sodium or its compartmentation into vacuoles is an important adaptive strategy for maize under salt stress. (5) Apoplastic acidification, required for cell wall extensibility, is an important indicator of salt resistance, but not essential for better maize growth under salt stress. (6) Upregulation of antioxidant defense genes and β-expansin proteins is important for salt resistance in maize. (7) Arbuscular mycorrhizal fungi improve salt resistance in maize due to better plant nutrient availability. (8) Seed priming is an effective approach for improving maize germination under salt stress. (9) Integration of screening, breeding and ion homeostasis mechanisms into a functional paradigm for the whole plant may help to enhance salt resistance in maize.

Description: Drought is a predominant cause of low yields worldwide. There is an urgent need for more water efficient cropping systems facing large water consumption of irrigated agriculture and high unproductive losses via runoff and evaporation. Identification of yield-limiting constraints in the plant–soil–atmosphere continuum are the key to improved management of plant water stress. Crop ecology provides a systematic approach for this purpose integrating soil hydrology and plant physiology into the context of crop production. We review main climate, soil and plant properties and processes that determine yield in different water-limited environments. From this analysis, management measures for cropping systems under specific drought conditions are derived. Major findings from literature analysis are as follows. (1) Unproductive water losses such as evaporation and runoff increase from continental in-season rainfall climates to storage-dependent winter rainfall climates. Highest losses occur under tropical residual moisture regimes with short intense rainy season. (2) Sites with a climatic dry season require adaptation via phenology and water saving to ensure stable yields. Intermittent droughts can be buffered via the root system, which is still largely underutilised for better stress resistance. (3) At short-term better management options such as mulching and date of seeding allow to adjust cropping systems to site constraints. Adapted cultivars can improve the synchronisation between crop water demand and soil supply. At long term, soil hydraulic and plant physiological constraints can be overcome by changing tillage systems and breeding new varieties with higher stress resistance. (4) Interactions between plant and soil, particularly in the rhizosphere, are a way towards better crop water supply. Targeted management of such plant–soil interactions is still at infancy. We conclude that understanding site-specific stress hydrology is imperative to select the most efficient measures to mitigate stress. Major progress in future can be expected from crop ecology focussing on the management of complex plant (root)–soil interactions.

Description: Intensive agriculture is often criticized for negative impacts on environment and human health. This issue may be solved by a better management of organisms living in crop fields. Here, we review the benefits of earthworms for crops, and we present techniques to increase earthworm abundance. The major points are the following: (1) Earthworms usually improve soil structural stability and soil porosity and reduce runoff. (2) Earthworms modify soil organic matter (SOM) and nutrient cycling. Specifically, earthworms stabilize SOM fractions within their casts, and they also increase the mineralization of organic matter in the short term by altering physical protection within aggregates and enhancing microbial activity. (3) The positive correlation between earthworm abundance and crop production is not systematic, and contrasting effects on yields have been observed. Earthworms induce the production of hormone-like substances that improve plant growth and health. (4) Direct drilling increases earthworm abundance and species diversity, but the beneficial effect of reduced tillage depends upon the species present and tillage intensity. (5) Organic amendments enhance earthworm abundance. (6) Earthworms feeding at soil surface are the most exposed to pesticides and other agrochemicals. Finally, we discuss how to combine management practices, including inoculation, to increase the earthworm services. We conclude that using earthworm services in cropping systems has potential to boost agricultural sustainability.

Description: Organic farming is mainly viewed as a homogeneous production system. Organic farming is also commonly thought to favor natural enemies of pests for crop protection. However, organic farming involves very different management practices and, in turn, various protection strategies. There is little knowledge on the influence of protection strategies on natural enemies in organic agriculture. Here, we analyzed crop protection strategies of 24 organic apple farmers in Southeast France. We also analyzed natural enemy communities in 12 apple orchards. We measured the impact of strategies on natural enemies using the International Organization for Biological and Integrated Control (IOBC) toxicity index. We identified four protection strategies: (1) the ecologically intensive strategy which promotes natural enemies by habitat management, (2) the substitution strategy mainly based on the use of pesticides, (3) the technologically intensive strategy which uses innovative technological methods such as exclusion nets and the integrated strategy which mobilizes a wide range of different practices. The IOBC toxicity index was 78.8 ± 23.0 for the substitution strategy, 60.75 ± 15.0 for the integrated strategy, 37.4 ± 11.9 for the ecological strategy, and 31.25 ± 1.7 for the technological strategy. We also found that the four strategies have different natural enemy communities such as the higher abundance of Forficula pubescens in the ecological strategy.

Description: Family farms in populated countries must produce sufficient quantities of food to meet the ever-growing population needs. It is unknown whether innovated farming systems can alleviate this issue. Here, we carried out field experiments in arid northwest China from 2009 to 2012 to determine the response of water use, grain yield, and water use efficiency. We integrated crop intensification via relay-planting and straw mulching in the same system. Straw mulching included stubble standing, straw covering, or straw incorporation to the soil. Results show that wheat and maize relay-planting with straw mulching increased yields by up to 153 % versus mono-planting of maize and wheat. Straw covering approached the highest yield. Relay-planting with stubble standing or straw covering decreased water consumption by 4.6 %. The integrated systems increased water use efficiency by up to 46 % compared to conventional mono-planting maize and wheat.

Description: Current pesticides such as methyl bromide are progressively removed from the market due to harmful residues in food. The stone fruit industries are thus seeking alternatives for postharvest control of insect pests. Microwave and radio frequency methods hold potential for postharvest thermal disinfestations of stone fruits to replace chemical fumigation. Knowledge of dielectric properties is essential for understanding the interaction between the electromagnetic fields and the target stone fruits and designing treatment beds in industrial applications. Here, we determined the dielectric properties of nectarine, peach, and plum between 10 and 1,800 MHz over a temperature range of 20–60 °C using an impedance analyzer. Our results show that the dielectric constant generally varied between 60 and 75, accounting for changes of 8–10 % due to temperature effect. But, the loss factor decreased linearly with frequency on the log scale at all temperatures for three stone fruits. The loss factor of Mediterranean fruit fly, nectarine, peach, and plum increased about 106, 108, 110, and 64 %, respectively, when the sample temperature increased from 20 to 60 °C. The penetration depth in all stone fruits decreased with increasing frequency and temperature. The loss factor ratio at 27 MHz of Mediterranean fruit fly to nectarine, peach, and plum was 1.65, 1.66, and 1.87 at 20 °C, respectively, suggesting potential differential heating between insects and host stone fruits in radio frequency treatments.

Description: Crop-damaging wireworms—the soil-dwelling larvae of click beetles—have resurged in Europe over the past 15 years, particularly in French maize crops. There is currently no curative treatment available to control wireworms, and preventive treatments are mainly chemical. We therefore need to better understand factors that rule damage for developing agroecological control strategies. In this investigation, we tested the effect of agricultural practices and local landscape on wireworm damage in maize crops. We surveyed wireworm damage in 341 fields under various conditions in western France in 2011 and 2012. We used in particular a random forest algorithm to impute missing values and an automated model selection routine to select the best beta regression model. Our results show that the occurrence of grassland in the rotation increases wireworm damage. Tillage also shows a high influence, though varying with season and year. Wireworm damage is decreased by the presence of hedges or cultivated crops at the field border, whereas it is increased by the presence of grassland at the field border. Overall, our findings provide some insights to develop preventive solutions for the sustainable control of wireworms, as well as a framework for data processing to analyze a wide range of similar situations involving other crops and pests.

Description: Glyphosate is a broad-spectrum systemic herbicide used to kill weeds, especially annual broadleaf weeds and grasses known to compete with commercial crops grown around the globe. However, weeds evolve and develop resistance to glyphosate. Until recently, no case of glyphosate resistance had been detected in France. Glyphosate resistance was indeed recently recorded in a Lolium rigidum weed population from a vineyard in the South of France. Here, we studied the mechanisms of this resistance case. Seed samples of L. rigidum were collected from the vineyard where resistance had been detected, as well as from a nearby area that had no known history of exposure to glyphosate. We studied the effect of retention of glyphosate spray, shikimic acid accumulation, glyphosate absorption and translocation, glyphosate metabolism, and the sequence of the enzyme that glyphosate targets in plants, 5-enolpyruvylshikimate-3-phosphate synthase. Our results show that glyphosate absorption decreased by 30 % in the resistant L. rigidum weed. In addition, glyphosate translocation out of the treated leaves was reduced by 52 %. Finally, the resistant biotype had a serine amino acid substitution at position 106 of the predicted protein, instead of the proline amino acid present in the susceptible population. Our results suggest that the resistant population of L. rigidum presents three different mechanisms of resistance to glyphosate, namely reduced absorption, reduced mobility in the plants, and a mutation in the gene coding for the enzyme targeted by glyphosate.

Description: Effective Microorganisms (EM®) is a “biofertiliser” soil inoculant, marketed as a crop yield enhancer. However, the literature has neither comprehensively reviewed its purported effects on harvests across multiple species nor investigated its effects on plant herbivore defence other than this group’s previous research on tomatoes. Here a meta-analysis of 39 journal articles and a greenhouse experiment with nine crop species afforded a nuanced assessment of Effective Microorganisms’ effects on plant growth and yield. Overall, in line with predictions, Effective Microorganisms showed significant positive effect on yield and growth (0.03 effect sizes increase) in the meta-analysis, and increased growth 16 % in the greenhouse, but with strong, and at times negative, species-specific responses. An additional potential benefit of Effective Microorganisms includes increased defence against herbivore attack, but inoculated corn ( Zea mays ) in a field and a greenhouse experiment exhibited decreased defences. Specifically, the field experiment demonstrated that Effective Microorganisms treatment corresponded to a 26 % reduction in predatory insect diversity on corn plants, while not improving growth or yield but did increase water uptake. A subsequent greenhouse experiment suggested likely physiological mechanisms behind the loss of predator diversity. When non-inoculated control corn plants were set upon by caterpillars of the herbivorous insect Spodoptera littoralis , the plants increased production of defensive volatile organic compounds (VOCs) by 272 %. Surprisingly, inoculation with Effective Microorganisms rendered greenhouse corn plants 51 % more palatable to S. littoralis . Further localised studies are, therefore, needed to efficiently incorporate Effective Microorganisms with either conventional or sustainable agricultural management systems.

Description: Agroecosystems represent 38 % of global land use. Agroecosystems are located close to human settlements and are managed to produce food and fibers, traded in markets. Agroecosystems also produce other goods and services essential to human beings, such as climate regulation, flood mitigation, and landscape amenity. Economists and ecologists have developed the ecosystem services framework to foster the provision of these non-commercial services. Scientists can therefore help decision makers to develop sustainable ecosystems by studying ecosystem services. Here, we analyze the trade-offs of ecosystem services of farming systems. We discuss case studies of mixed perennial crops. The set of ecosystem services provided by these agroecosystems depends on their composition, structure, and management. Complex rule-based management will be required if winegrowers are to maintain an adequate set of ecosystem services across contrasting climatic years. Innovations including cover crops in banana systems can fulfill most of the objective set but will rely on increased farm labor. We then discuss the advantages, challenges, and opportunities to include the description of relations between ecosystem services in cropping system design. We propose to extend the yield gap analysis to ecosystem services, as a service gap analysis. This extension faces methodological questions about the potential provision of a service in a region. We conclude on the challenges that need to be faced if we want to use ecosystem services trade-offs to improve the contribution of agricultural systems to human well-being.