Kinetics of maize cob and bean straw pyrolysis and combustion.

Kinetic studies are important for the design and optimisation of thermochemical processes. This study involved analysis of the pyrolysis and combustion behaviour of the agricultural residues (bean straw and maize cob) by non-isothermal thermogravimetric analysis. Increasing the heating rate from 10 to 40 K min-1 during both combustion and pyrolysis increased the degradation rate of both feedstocks and the gaseous yields of H2O, CO and CO2. The activation energies determined by the Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose methods varied which reveals that the pyrolysis and combustion of these agricultural residues are complex processes involving multiple reactions. The average activation energy of maize cob and bean straw were 214.15 and 252.09 kJ mol-1 for pyrolysis and 202.26 and 165.64 kJ mol-1 for combustion, respectively. The order of reaction ranged between 9.0-10.3 and 6.3-13.3 for both feedstocks in combustion and inert environments, respectively. Modelled data is important to enable the optimisation of reactor design for pyrolysis and combustion for energy generation from agricultural residues.

Breeding Bread-Making Wheat Varieties for Organic Farming Systems: The Need to Target Productivity, Robustness, Resource Use Efficiency and Grain Quality Traits.

Agronomic protocols (rotation, tillage, fertilization and crop protection) commonly used in organic and conventional crop production differ significantly and there is evidence that modern varieties developed for conventional high-input farming systems do not have the combination of traits required for optimum performance in organic farming systems. Specifically, there is evidence that prohibition on the use of water-soluble, mineral N, P and K fertilizers and synthetic pesticide inputs in organic farming results in a need to revise both breeding and selection protocols. For organic production systems, the focus needs to be on the following: (i) traits prioritized by organic farmers such as high nutrient use efficiency from organic fertilizer inputs, competitiveness against weeds, and pest and disease resistance, (ii) processing quality parameters defined by millers and bakers and (iii) nutritional quality parameters demanded by organic consumers. In this article, we review evidence from variety trials and factorial field experiments that (i) studied to what extent there is a need for organic farming focused breeding programs, (ii) investigated which traits/trait combinations should be targeted in these breeding programs and/or (iii) compared the performance of modern varieties developed for the conventional sector with traditional/older varieties favored by organic farmers and/or new varieties developed in organic farming focused breeding programs. Our review focuses on wheat because there have been organic and/or low-input farming focused wheat breeding programs for more than 20 years in Europe, which has allowed the performance of varieties/genotypes from organic/low-input and conventional farming focused breeding programs to be compared.

Effect of irrigation, fertiliser type and variety on grain yield and nutritional quality of spelt wheat (Triticum spelta) grown under semi-arid conditions.

Previous studies reported higher antioxidant and mineral micronutrient concentrations in organic compared to conventional wheat flour, but the reasons are poorly understood. Here we report results from a long-term, factorial field experiment designed to assess effects of variety choice, supplementary irrigation and contrasting fertilization regimes used in organic and conventional production on the nutritional quality and yield of spelt wheat grown in a semi-arid environment. Long-straw (Oberkulmer, Rubiota, ZOR) varieties had 10-40% higher grain Cu, Fe, Mn and Zn concentrations, while the modern, short straw variety Filderstolz had 15-38% higher grain antioxidant activity. Supplementary irrigation and the use of manure instead of mineral NPK as fertilizer had no substantial effect on the nutritional composition of spelt grain, but increased grain yields by ~ 150 and ~ 18% respectively. Overall, this suggests that breeding/variety selection is the most promising approach to improve the nutritional quality of spelt grain in semi-arid production environments.

The impact of the EU neonicotinoid seed-dressing ban on oilseed rape production in England.

BACKGROUND: Neonicotinoid seed dressings on oilseed rape were banned in the European Union (EU) from December 2013. A survey of > 200 farms was conducted in England in the 2014/15 and 2015/16 seasons to assess the impact of the ban on changes in crop area, crop losses to cabbage stem flea beetle (CSFB), insecticide use and the economics of oilseed rape production. RESULTS: The area of oilseed rape grown fell in both seasons, with CSFB identified as the third most important reason for the decrease. Crop losses to CSFB were 3% and 5% in the respective seasons, with clear variation by county. There were clear differences in the crop area treated (1.14 vs 0.77 million ha) and the number of insecticide applications per crop (2.0 vs 1.4) to combat CSFB in 2014/15 and 2015/16, respectively. Within the derogation area counties there was a clear reduction in the number of applications per crop when neonicotinoid-treated vs non-treated seed was used (1.0 vs 1.9), respectively. CONCLUSION: Increasing resistance to pyrethroid insecticides in combination with the neonicotinoid seed dressing ban is likely to have significant impacts on the viability of growing oilseed rape in England particularly where CSFB activity/risk is high. © 2018 Society of Chemical Industry.

Effects of Agronomic Management and Climate on Leaf Phenolic Profiles, Disease Severity, and Grain Yield in Organic and Conventional Wheat Production Systems.

Agricultural intensification over the last 40 years has increased cereal yields, but there is very limited information on the effects of intensification practices (e.g., nondiverse rotations, mineral NPK fertilizer, and pesticides) on crop health and quality. Results from the study reported here suggest that the use of mineral NPK fertilizers reduces phenolic acid and flavonoid concentrations in leaves and increases the susceptibility of wheat to lodging and powdery mildew, when compared to composted FYM inputs. In contrast, the use of herbicides, fungicides, and growth regulators reduces lodging and foliar disease severity but had no effect on phenolic acid and flavonoid concentrations. The use of composted FYM inputs also resulted in a significant grain yield reduction and not substantially reduced the severity of opportunistic pathogens such as Septoria, which remain a major yield limiting factor unless fungicides are used and/or more Septoria resistant varieties become available.