Organic farming and resource efficiency

The Chapter discusses the efficiency of nutrient and energy use in organic farming, regarding the pressing need to make efficient use of natural resources. Nutrient recycling, the use of adapted plant varieties and energy-saving through the ban of synthetic nitrogen fertilizer are organic farming practices that enhance resource efficiency

Barriers to Agro-Ecological Intensification of Smallholder Upland Farming Systems in Lao PDR

Intercropping of legumes can be a strategy to improve soil fertility and enhance overall productivity while reducing dependency on external inputs in intensified cropping systems. Integration of legumes in maize-based cropping systems is promoted as an agro-ecological intensification option for input-constrained smallholders in uplands of Southeast Asia, but adoption rates in the region remain low. The overall aim of this study was to assess the suitability and trade-offs of integrating ricebean in maize-based smallholder cropping systems in upland areas of Northern Laos. We conducted a researcher-managed field trial to investigate the agronomic performance of ricebean/maize intercropping, and farmer-managed trials combined with surveys (N = 97), and focus group discussions in 10 villages to understand factors influencing farmers’ decision making concerning ricebean adoption. Drought, rat infestation and crop damage by grazing livestock were identified as important constraints to the production of ricebeans. Factors facilitating adoption included improvement of soil fertility, the potentially high selling price of ricebeans and the presence of extension agents, while barriers included labour shortage, concerns about competition with maize and lack of a market outlet for the ricebean produce. We conclude that the investigated maize/ricebean intercropping system is poorly suited to the current conditions in the study area, and call for farm-based studies focusing on developing locally adapted legume intercropping systems able to perform under variable rainfall conditions. Initiatives addressing challenges related to free grazing livestock and efforts to link legume producers in remote areas to emerging markets are also needed

Organic farm conventionalisation and farmer practices in China, Brazil and Egypt.

Certified organic agriculture stipulates a range of principles and standards, which govern farmer practices. The recent global expansion of organic agriculture has raised new challenges for organic agriculture, particularly whether management practices in organic farms are subject to the forces of conventionalisation. We studied changes in agroecological practices in certified organic farms in China, Brazil and Egypt. The study takes departure in the conventionalisation hypothesis and the analysis is framed using organic and agroecological principles. The study focuses on agroecological design principles, inherent to organic agriculture, of diversity in crop production, pest, disease and weed management, and soil fertility management. The research design was as a multiple case study of five cases in China, Brazil and Egypt. We show that the adoption of organic agriculture has induced fundamental changes in organic farmer management practices, although agroecological practices of organic farmers do not fulfil organic principles. The forces of conventionalisation exert a strong influence on changes in organic farmer practices. Organic ‘niche’ market crops with a high-value influence organic farmers’ management decisions, particularly regarding the prioritisation of diversity in the cropping systems for agroecological purposes. The farming systems have therefore not undergone major changes of their cropping patterns. Furthermore, there was a general heavy reliance upon input substitution for pest and soil fertility management. This study thus presents new data and a novel analysis of the implications at the farm scale of the global expansion of organic agriculture, and the influence of conventionalisation on farmers practices

The effect of Penicillium bilaii on wheat growth and phosphorus uptake as a ected by soil pH, soil P and application of sewage sludge

Background: Penicillium bilaii may enhance P availability to plants, since it has been shown to increase plant growth and P uptake. There is currently increasing interest in using microorganisms to promote P mobilisation from organic P sources. An investigation was conducted to determine the e ects of P. bilaii on P uptake and growth of wheat in the presence and absence of sewage sludge. Two soils di ering in P contents and pH were used, as it was hypothesised that these a ect the e ciency of P mobilisation. Methods: A pot experiment, in which wheat was grown for 35 days in a moderately acidic soil of low P status and a calcareous soil of moderate P status, was conducted. A full factorial design was used with two non‐sterilised soils, three amendments [control, sewage sludge and triple superphosphate (TSP)] and two P. bilaii treatments (with/ without). Shoot and root length, biomass and nutrient contents were analysed in plant, whereas soil samples were analysed for water‐extractable P and soil pH. Results: The shoot length and root biomass of wheat were signi cantly higher when sewage sludge was applied in combination with P. bilaii seed inoculation, in the moderately acidic soil. In contrast, shoot length and biomass and root biomass were higher with P. bilaii compared to the control, but no synergistic e ects of P. bilaii and the organic P source were observed in the calcareous soil. A systematic, but not signi cant increase in total P uptake was found for all treatments inoculated with P. bilaii and for both soils, with the control of the low fertility moderately acidic soil being a notable exception. Conclusions: Sewage sludge was seen to be an e cient P source, on par with TSP in the moderately acidic soil. In the calcareous soil, the P. bilaii treatments without added P fertilisers had the greatest e ect, with both root and shoot biomass increasing signi cantly