ALBERT

Description: SUMMARYIn the present study, carried out in South-eastern Spain, a commercial arbuscular mycorrhizal fungus (AMF;Glomus iranicumvar.tenuihypharumsp.nova) was introduced through drip irrigation to inoculate Crimson grapevines. Their effects on the physiological and nutritional activity were evaluated for 2 years (2011–12). Additionally, during the second year of experimentation, the persistence of mycorrhizae on the grapevine and their effects were innovatively analysed.The AMF satisfactorily colonized the Crimson grapevine roots, improved the plants water status, induced an improvement in the photosynthetic performance that increased the water use efficiency, promoted the uptake of phosphorus (P), potassium (K) and calcium (Ca) and led to a mobilization of starch reserves in the apex in winter, which was possibly responsible for enhancing root development. Moreover, inoculated plants had significantly increased yield and improved quality of grapes, which led to early grape maturation. Overall, the persistent effect of AMF during the second year produced similar positive effects, although to a lesser extent, to those obtained in the inoculated treatment.The results found in the present study show that this AMF application technique can be recommended for sustainable agriculture in arid and semi-arid areas. Moreover, as a result of the competition with the native mycorrhizae, periodic monitoring of the percentage of mycorrhizal colonization and re-inoculation in order to obtain all the positive effects evidenced in the inoculated treatment is recommended.

Description: SUMMARYCurrent production systems for crops, meat, dairy and bioenergy in the European Union (EU) rely strongly on the external input of nitrogen (N). These systems show a high productivity per unit of land. However, the drawback is a complex web of N pollution problems contributing in a major way to degradation of ecosystems. European Union Directives and national policies have improved nutrient management and reduced fertilizer N use in most European countries, which has curbed the N pollution trends particularly in regions with high stocking rates of animals. However, improvement is slowing down and environmental targets for N are not within reach. Building on the 2011 European Nitrogen Assessment, the current paper reviews key features of the complex relationships between N use and food production in Europe in order to develop novel options for a more N-efficient, less N-polluting and secure European food system. One option is to relocate feed and livestock production from Northwestern to Central and Eastern Europe. This would allow a reduction of N rates and N pollution in cereal production in Northwest Europe by 30% (50 kg N/ha), while increasing total cereal production in Europe. Another option is a change towards legume-based cropping systems to produce animal feed, in order to decrease dependence on N fertilizer and feed imports. The greatest challenge for Europe is to decrease the demand for feed commodities, and thus for land and N, by a shift to more balanced (and healthier) diets with less animal protein. These drastic changes can be stimulated by targeted public–private research funding, while the actual implementation can be enhanced by smart payment schemes using, for example money from the Common Agricultural Policy, certification and agreements between stakeholders and players in the food and energy chain. Involving networks of consumers, producers and non-governmental organizations is critical. An effective strategy starts with convincing consumers with a Western diet to eat less meat and dairy by communicating the associated health benefits and smaller ecological footprints. Internalizing the cost of N pollution leading to increased prices for N-intensive food products may also enhance involvement of consumers and provide financial resources to compensate farmers for loss of income and extra costs for stricter N measures.

Description: SUMMARYThe objective of the current study was to determine whether exposure to an artificial long-day photoperiod increases milk production in subtropical goats maintained under extensive grazing conditions, with or without the presence of a nutritional supplement. Forty-four lactating goats were exposed to a natural photoperiod (11 h light) with nutritional supplementation (NDS; natural day supplemented group; n=11) or without nutritional supplementation (NDN; natural day non-supplemented group; n=11) or to an artificial long-day photoperiod (16 h light) with nutritional supplementation (LDS; long-day supplemented group; n=11) or without nutritional supplementation (LDN; long-day non-supplemented group; n=11). Daily nutritional supplementation consisted of a mixture of 300 g rolled maize and 200 g soya bean per animal. During the suckling phase, milk yield was assessed at 10 and 20 days lactation and thereafter every 10 days up to 110 days lactation from day 40 of lactation. Plasma insulin-like growth factor 1 (IGF-I) concentration was determined at 20, 40, 60, 80 and 100 days of lactation. Mean milk yield was greater in goats from the LDN group than the NDN group. The difference in mean milk yield was greater when goats received a nutritional supplement. With nutritional supplementation, the plasma IGF-I concentrations were greater in goats exposed to long days than in those maintained under natural photoperiod. However, IGF-I concentrations were lower with long days when goats were not supplemented. In conclusion, exposure to an artificial long-day photoperiod increases milk yield in subtropical lactating goats maintained under extensive grazing conditions, and this increased milk production is more pronounced with a nutritional supplement. Furthermore, depending on nutritional status, exposure to artificial long days increases plasma IGF-I concentration in lactating goats.

Description: 1. Fifty-one experiments on the nitrogen, phosphate and potash requirements of maincrop potatoes were carried out in Great Britain in 1956–62. Each experiment tested four rates of each nutrient in all combinations and both total and riddled yields and quality data were obtained.2. Nitrogen requirement was influenced by previous cropping and the rainfall during the preceding winter. 50–80 lb/acre of N are recommended in mixed farming rotations depending on winter rainfall, and 120–150 lb/acre of N in arable rotations.3. Yield increases from phosphate were usually larger on soils with low citric-soluble phosphate. Nevertheless, irrespective of soil phosphate status, optimum rates of application were at least 120 lb/acre of P2O5 which was the highest rate tested in most of the experiments.

Description: SUMMARYSilage maize variety testing systems usually evaluate new varieties within properly defined maturity groups; within a maturity group, all varieties are harvested on a single harvest date. In a small country like Belgium where growing conditions are similar across the maize growing areas, all tested silage maize varieties, comprising different maturity groups, are harvested on a single date. Under this testing system, only few varieties are harvested at the physiological stage where they theoretically show their optimal performance. In the current research, eight silage maize varieties were monitored from 25 to 40% whole-crop dry matter (DM) content at three locations in Belgium during the period 2007–2009. The optimal harvest date was calculated as the date where whole-crop DM yield, ear DM yield and organic matter digestibility were maximal. The variety rank at the optimal harvest date was compared with the variety rank at any studied single harvest date. Harvest dates where the variety rank was not statistically different to the rank at the optimal harvest date were pooled in a ‘harvest window’. Based on the current data, the harvest window comprised a flexible harvest period of about 14 days. It was therefore concluded that applying a single harvest date is scientifically justified for the ranking of silage maize varieties in Belgium, when the whole-crop DM content is between 28·1 and 40·6% with a maximum difference of 7·2% between all compared varieties.

Description: SUMMARYThe objective of the present study was to calculate an optimal harvest period for both fresh and ensiled samples of forage maize and to calculate a set of harvest dates (called a harvest window), for which the variety ranking of the fresh forage corresponds with the variety ranking at the optimal harvest period calculated from the ensiled forage. Forage maize is fed almost exclusively as silage, but official variety trials with silage maize determine quality parameters in fresh (i.e. non-preserved) forage. Eight silage maize varieties were monitored at six harvest dates (from 25 to 40% dry matter content) in Merelbeke (Belgium) in 2013–15. At each harvest date, fresh samples were taken and half of the sampled material was ensiled in micro silos for 20 weeks. An optimal harvest period was calculated based on frequently measuring starch concentration and organic matter digestibility for both fresh and ensiled forage. Eventually, harvesting the silage maize at a dry matter content of 32–35% guaranteed an optimal harvest period. Based on the results of eight varieties, reporting variety ranks without going through the ensiling process continues to be a scientifically justified practice in Belgian official variety trials. Varieties with a superior fresh quality keep their leading position after ensiling, but variety differences become smaller after ensiling.

Description: SUMMARYMineralized soil nitrogen (N) is an important source of N for grassland production. Some soils can supply large quantities of plant-available N through mineralization of soil organic matter. Grass grown on such soils require less fertilizer N applications per unit yield. A reliable, accurate and user-friendly method to account for soil N supply potential across a large diversity of soils and growing conditions is needed to improve N management and N recommendations over time. In the current study, the effectiveness of chemical N tests and soil properties to predict soil N supply for grass uptake across 30 Irish soil types varying in N supply potential was investigated under controlled environmental conditions. The Illinois soil N test (ISNT) combined with soil C : N ratio provided a good estimate of soil N supply in soils with low residual mineral N. Total oxidized N (TON) had the largest impact on grass dry matter (DM) yield and N uptake across the 30 soil types, declining in its influence in later growth periods. This reflected the high initial mineral N levels in these soils, which declined over time. In the current study, a model with ISNT-N, C : N and TON (log TON) best explained variability in grass DM yield and N uptake. All three rapid chemical soil tests could be performed routinely on field samples to provide an estimate of soil N supply prior to making N fertilizer application decisions. It can be concluded that these soil tests, through their assessment of soil N supply potential, can be effective tools for N management on grassland; however, field studies are needed to evaluate this under more diverse growing conditions.

Description: SUMMARYEffects of the correction of microbial contamination (using15N techniques) and of considering the comminution rate (kc) of particles in the rumen on effective estimates of the ruminally undegraded (RU) fraction and its intestinal effective digestibility (IED) were examined in a sample of dehydrated sugar beet pulp (DBP) generating composite samples (from rumen-incubated residues) representative of the chemical composition of RU. Tested fractions were dry matter (DM), organic matter (OM, tested only for RU), crude protein (CP) and amino acids (AA). The study was performed on three rumen and duodenum cannulated wethers fed with a 2 : 1 (fresh weight basis) chopped oat hay-to-concentrate diet supplied at 40 g DM/kg BW0·75in six equal meals per day. The DBP showed sigmoid degradation kinetics: the fractional degradation rate increased by 5·8 times as time (h) increased from 0 to∞. Thekcrate (measured in the diet concentrate) represented 5·74% of the total rumen retention time of particles. As a result, the RU of DM was over-evaluated by 6·53% whenkcwas not considered. Microbial contamination of RU was high as in DM as in CP. Therefore, the overestimation of RU of DM was increased to 12·2% when this contamination was not corrected. The lack of this correction also led to large over-evaluations of RU and IED of CP and AA. As a result, the overestimation of the intestinal digested fraction was 40·9% for CP and 45·0% for total analysed AA. This overestimation varied largely among AA (from 18·9 to 88·7%). Corrected proportions of RU and IED were also variable among AA. Hypotheses on the causes of this variability are given. Resultant changes in the AA profile of the intestinal digested protein had some negative impact on the supply of essential AA and cysteine without affecting lysine. This problem is limited because the microbial protein synthesized from DBP fermentation in the rumen is largely predominant in the AA supply to the host.

Description: Integrated crop-livestock systems (ICLS) are currently promoted agricultural production systems that aim to use better resources through production integration and intensification. While this system reduces some risks, it adds complexity and new risks to businesses due to interdependence between the agricultural modules. To deal with these issues, integrated risk management is required to reduce the effects of risks and to take advantage of the opportunities of an ICLS. Generically, enterprise risk management (ERM) meets this need by proposing comprehensive and coherent risk management, instead of managing agricultural module risks individually. However, there is a need to customize the ERM approach to ICLS. Therefore, the current study aims to develop a method to manage risks for ICLS based on ERM, integrating the management of risks and aligning risk management with the strategic objectives. A literature review, a pilot study, interviews with experts, four case studies and 20 practitioners supported the method development and evaluation through three versions. As a result, the method identifies and relates risks through process mapping with a qualitative and quantitative analysis of their impacts, determines risk responses based on willingness to take risks, and helps identify processes to control, communicate and monitor the risks. The method also stimulates the implementation of ICLS in market-oriented farms, providing an approach to increase the chances of ICLS success. The main difference from previous research lies in the integrative management of multiple risks, the alignment of risks with strategy and the consideration that a risk might be considered an opportunity.

Description: SUMMARYPhenological models are considered key tools for the short-term planning of viticultural activities and long-term impact assessment of climate change. In the present study, statistical phenological models were developed for budburst (BUD), flowering (FLO) and veraison (VER) of 16 grapevine varieties (autochthonous and international) from the Portuguese wine-making regions of Douro, Lisbon and Vinhos Verdes. For model calibration, monthly averages of daily minimum (Tmin), maximum (Tmax) and mean (Tmean) temperatures were selected as potential regressors by a stepwise methodology. Significant predictors included Tmin in January–February–March for BUD, Tmax in March–April for FLO, and Tmin, Tmax and Tmean in March–July for VER. Developed models showed a high degree of accuracy after validation, representing 0·71 of total variance for BUD, 0·83 for FLO and 0·78 for VER. Model errors were in most cases 〈 5 days, outperforming classic growing degree-day models, including models based on optimized temperature thresholds for each variety. Applied to the future scenarios RCP4·5/8·5, projections indicate earlier phenophase onset and shorter interphases for all varieties. These changes may bring significant challenges to the Portuguese wine-making sector, highlighting the need for suitable adaptation/mitigation strategies, to ensure its future sustainability.