ALBERT

Description: Nitrate vulnerable zones (NVZs) are areas considered to be at high risk of water pollution due to an excess of nitrates and, according to European regulations, codes of good agricultural practice are to be implemented by farmers, such as reducing doses of the applied fertilizers, or the use of fertilizers that minimize nitrate leaching. In this work, the influence of organic fertilization with dried pig manure (DPM) as compared to mineral fertilization with ammonium sulfate nitrate with 3,4-dimethylpyrazole phosphate nitrification inhibitor was studied in a barley crop planted in a NVZ in Fompedraza (Valladolid, Spain). Organic and mineral fertilizers were applied at different rates (85, 133 and 170 kg N·ha−1·year−1 vs. 90 and 108 kg N·ha−1·year−1, respectively) over a three-year period, in a randomized complete block design with six treatments and four blocks. DPM-based fertilization resulted in a 65% increase in crop yield as compared to the control soil, reaching 1800 kg·ha−1 for an application rate of 85 kg N·ha−1·year−1. Higher DPM rates were found to increase the electrical conductivity and assimilable phosphorus, potassium, magnesium and organic matter contents, but did not lead to yield enhancements. Final nitrate and ammonium concentrations were lower than 10 mg·kg−1 and 20 mg·kg−1, respectively, and no increase in soil salinity or heavy metal pollution was observed. DPM fertilization should be supplemented with small doses of inorganic fertilizers to obtain crop yields similar to those attained with mineral fertilization.

Description: This paper reports the results on the agronomic performance of organic amendments in the EU 7th FP project “FERTIPLUS—reducing mineral fertilizers and agro-chemicals by recycling treated organic waste as compost and bio-char”. Four case studies on field-scale application of biochar, compost and biochar-blended compost were established and studied for three consecutive years in four distinct cropping systems and under different agro-climatic conditions in Europe. These included the following sites: olive groves in Murcia (Spain), greenhouse grown tomatoes in Almeria (Spain), an arable crop rotation in Oost-Vlaanderen (Merelbeke, Belgium), and three vineyards in Friuli Venezia Giulia (Italy). A slow pyrolysis oak biochar was applied, either alone or in combination with organic residues: compost from olive wastes in Murcia (Spain), sheep manure in Almeria (Spain), and compost from biowaste and green waste in Belgium and Italy. The agronomical benefits were evaluated based on different aspects of soil fertility (soil total organic carbon (TOC), pH, nutrient cycling and microbial activity) and crop nutritional status and productivity. All amendments were effective in increasing soil organic C in all the field trials. On average, the increase with respect to the control was about 11% for compost, 20% for biochar-blended compost, and 36% for biochar. The amendments also raised the pH by 0.15–0.50 units in acidic soils. Only biochar had a negligible fertilization effect. On the contrary, compost and biochar-blended compost were effective in enhancing soil fertility by increasing nutrient cycling (25% mean increase in extractable organic C and 44% increase in extractable N), element availability (26% increase in available K), and soil microbial activity (26% increase in soil respiration and 2–4 fold enhancement of denitrifying activity). In general, the tested amendments did not show any negative effect on crop yield and quality. Furthermore, in vineyards and greenhouse grown tomatoes cropping systems, compost and biochar-blended compost were also effective in enhancing key crop quality parameters (9% increase in grape must acidity and 16% increase in weight, 9% increase in diameter and 8% increase in hardness of tomato fruits) important for the quality and marketability of the crops. The overall results of the project suggest that the application of a mixture of biochar and compost can benefit crops. Therefore, biochar-blended compost can support and maintain soil fertility.

Description: Lemon processing generates thousands of tons of residues that can be preserved as flours by thermal treatment to obtain phenolic compounds with beneficial bioactivities. In this study, the effect of different drying temperatures (40, 50, 60, 70, 80, 90, 100 and 110 °C) on the Total Phenolic Content (TPC), antioxidant and antimicrobial activities of phenolic compounds present in Citrus. lemon (L.) Burn f waste was determined. Identification and quantification of phenolic compounds were also performed by UPLC-PDA and UPLC-ESI-MS analysis. Eriocitrin (19.79–27.29 mg g−1 DW) and hesperidin (7.63–9.10 mg g−1 DW) were detected as the major phenolic compounds in the flours by UPLC-PDA and confirmed by UPLC-ESI-MS. Antimicrobial activity determined by Minimum Inhibitory Concentration (MIC) against Salmonella typhimurium, Escherichia coli and Staphylococcus aureus was observed. Accordingly, a stable functional flour as a source of bioactive phenolic compounds obtained from lemon residues at 50 °C may be produced as a value-added product useful in various industrial sectors.

Description: The objective of this research was to evaluate the production and phytochemical quality of cucumber (Cucumis sativus) fruits, in response to the foliar application of different seaweed extracts. This study was carried out under shadow mesh conditions in the autumn–winter agricultural cycle at the Instituto Tecnológico de Torreón, Torreón, Coahuila, Mexico. The experimental design was completely random, using six treatments with six repetitions each. The treatments evaluated were: Macrocystis pyrifera, Bryothamnion triquetrum, Ascophyllum nodosum, Grammatophora spp., Macrocystis integrifolia, and a control treatment with inorganic fertilization. The substrate used was a mixture of sand and vermicompost. The yield, commercial size, and phytochemical compounds of the fruit were evaluated. Results showed that the yield using Steiner solution (6.75 kg m−2) was higher than that obtained with Bryothamnion triquetrum algae (6.07 kg m−2). Regarding the phenolic content, the extracts surpassed the control treatment, with Macrocystis pyrifera and Macrocystis integrifolia being statistically equal, with values of 47.37 and 43.73 mg equiv. of Ac. Gallic 100 g fresh weight, respectively. The antioxidant capacity by ABTS+ and DPPH+ methods was higher using the treatment with Macrocystis pyrifera algae with 149.4 and 454.1 μM equiv Trolox/100 g fresh base, respectively. This treatment also presented the highest value of vitamin C with 5.07 mg/100 g fresh base, being 27% greater than the control treatment. Algae extracts increased the quality of the fruits by obtaining the highest antioxidant capacity, making their use a viable option to minimize the application of conventional fertilizers, thereby attenuating the effects on the environment and improving the health of the population.

Description: The introduction of nanofertilizers (Nfs) in agriculture has allowed the development of new technologies that enhance the productivity of crops. Within the most studied Nfs we find metal oxides, especially ZnO; however, the results of various experiments provide contradictory data on the growth variables. Therefore, this study intended to evaluate the efficiency associated with the use of nanoparticles, sulfates, and zinc-chelates in Phaseolus vulgaris L. cv. Strike grown in acid soil, as well as to evaluate its production, total biomass, and nitrogen assimilation. Phaseolus vulgaris L. cv. Strike plants were sprouted and grown in polyethylene bags containing 3 kg of acid soil (pH 6.8) in an experimental greenhouse and were watered with a nutritious solution. A completely randomized design including ten treatments and five repetitions was used. Treatments consisted of applying different zinc sources (sulfate, DTPA chelate, and zinc oxide nanoparticles) to four different doses (0, 25, 50, and 100 ppm of zinc). Results obtained indicated that the doses best favoring an increase in biomass, production, and nitrogen assimilation were 50 ppm of ZnSO4, 100 ppm of DTPA-Zn, and 25 ppm of zinc oxide nanofertilizers (NfsOZn). Hence, the dose containing 25 ppm of NfsOZn was the most efficient dose, since at a lower dose it was able to equalize biomass accumulation, production, and nitrogen assimilation as compared to ZnSO4 and DTPA-Zn sources. However, further research is required, given that high-concentration doses were toxic for beans. Finally, it is worth highlighting that zinc oxide nanoparticles have a huge potential to be used as nanofertilizers if applied in optimal concentrations.

Description: Roots are crucial for adaptation to drought stress. However, phenotyping root systems is a difficult and time-consuming task due to the special feature of the traits in the process of being analyzed. Correlations between root system architecture (RSA) at the early stages of development and in adult plants have been reported. In this study, the seminal RSA was analysed on a collection of 160 durum wheat landraces from 21 Mediterranean countries and 18 modern cultivars. The landraces showed large variability in RSA, and differences in root traits were found between previously identified genetic subpopulations. Landraces from the eastern Mediterranean region, which is the driest and warmest within the Mediterranean Basin, showed the largest seminal root size in terms of root length, surface, and volume and the widest root angle, whereas landraces from eastern Balkan countries showed the lowest values. Correlations were found between RSA and yield-related traits in a very dry environment. The identification of molecular markers linked to the traits of interest detected 233 marker-trait associations for 10 RSA traits and grouped them in 82 genome regions named marker-train association quantitative trait loci (MTA-QTLs). Our results support the use of ancient local germplasm to widen the genetic background for root traits in breeding programs.

Description: Piquin pepper (Capsicum annuum var. glabriusculum) is an important species that supports the economy of rural households; it is part of Mexican gastronomy and it is a highly valuable phytogenetic resource. There has been recent interest in domesticating and exploiting piquin pepper commercially, which has been limited until now due to the low germination rate, and this work had the purpose of promoting germination and determining the physiological capacity of genotypes. Ten piquin pepper genotypes from different geographical origins in Mexico were submitted to 11 pre-germination treatments. A completely randomized experimental design was carried out with arrangement in split-plot. The large plot had the treatments and the small plot had the genotypes. The results showed differences (p 〈 0.01) among treatments, genotypes, and treatment–genotype interaction. On one hand, treatments gibberellic acid (GA) and mechanical scarification + gibberellic acid (MSGA) increased the physiological potential of genotypes, reaching the highest values of germination speed (GS), germination index (IG) and germination percentage (GP); as well as the lowest values of dead seeds (DS) and hard Seeds (HS). In turn, the genotypes that presented the same condition were G8, G7, and G10. Regarding the interaction, each variable had a different condition. In conclusion, we can increase the physiological potential and solve the dormancy of piquin pepper seed by applying gibberellic acid. Likewise, the best genotypes were G8 and G10.

Description: Agronomy, Vol. 8, Pages 147: Impact of Climatic Variables on Carbon Content in Sugar Beet Root Agronomy doi: 10.3390/agronomy8080147 Authors: Luis F. Sánchez-Sastre Pablo Martín-Ramos Luis M. Navas-Gracia Salvador Hernández-Navarro Jesús Martín-Gil The impacts of climatic variables on the growth and carbon content of spring sown sugar beet (Beta vulgaris L.) in the Castilla y Leon region (Northwestern Spain) were assessed by analyzing 35 beet crop variables at four sites over two cultivation years. ANOVA analysis allowed to discern that the location was the factor that had the highest effect on those variables. Fertilization treatments only had a significant impact on the variables derived from the quantity of fresh material (leaves), while the beet variety choice influenced the amount of nitrogen in leaves and the carbon to nitrogen ratio. It could be inferred that the percentage of root carbon content depended mostly on the location and that a higher percentage of root carbon content led to a higher content of dry matter, with a positive relationship with the sucrose content for the two types of varieties that were tested. Principal Component Analysis distinguished the climatic factors that most influenced each cultivation area in each cultivation year and provided a clear separation of the data in clusters, evidencing the uniqueness of each site.

Description: Saline stress severely affects the growth and productivity of plants. The activation of hormonal signaling cascades and reactive oxygen species (ROS) in response to salt stress are important for cellular detoxification. Jasmonic acid (JA) and the enzyme SOD (superoxide dismutase), are well recognized markers of salt stress in plants. In this study, the application of chitosan-polyvinyl alcohol hydrogels (Cs-PVA) and copper nanoparticles (Cu NPs) on the growth and expression of defense genes in tomato plants under salt stress was evaluated. Our results demonstrate that Cs-PVA and Cs-PVA + Cu NPs enhance plant growth and also promote the expression of JA and SOD genes in tomato (Solanum lycopersicum L.), under salt stress. We propose that Cs-PVA and Cs-PVA + Cu NPs mitigate saline stress through the regulation of oxidative and ionic stress.

Description: The impacts of climatic variables on the growth and carbon content of spring sown sugar beet (Beta vulgaris L.) in the Castilla y Leon region (Northwestern Spain) were assessed by analyzing 35 beet crop variables at four sites over two cultivation years. ANOVA analysis allowed to discern that the location was the factor that had the highest effect on those variables. Fertilization treatments only had a significant impact on the variables derived from the quantity of fresh material (leaves), while the beet variety choice influenced the amount of nitrogen in leaves and the carbon to nitrogen ratio. It could be inferred that the percentage of root carbon content depended mostly on the location and that a higher percentage of root carbon content led to a higher content of dry matter, with a positive relationship with the sucrose content for the two types of varieties that were tested. Principal Component Analysis distinguished the climatic factors that most influenced each cultivation area in each cultivation year and provided a clear separation of the data in clusters, evidencing the uniqueness of each site.