Reducing methane emission and maintaining rice sustainable production are two major challenges in rice production. Scientists Xu et al. showed that planting the free-floating water fern Azolla along with double rice reduced methane emission in rice paddies due to significant effect on dissolved oxygen and soil redox potential, which are key factors for methane emission.
Agriculture contributes significantly to greenhouse gas emissions and there is a need for identifying viable long term reduction steps that farmers can adopt. Scientists Dumbrell et al. identified the greenhouse gas mitigation potential and the costs of abatement at three Australian grain farms located in the main grain growing regions of Australia. They found marked difference in abatement potential and impact on operating profits across case study farms and management practices. Reaching significant climate change abatement will come at a cost to farmers.
There is a feeling that hybrids are better adapted than open-pollinated cultivars to manage with climate change. However, scientists Lana et al. investigated maize cultivars responses to temperature and precipitation changes and report an equivalent or even better resilience of open-pollinated cultivars compared with hybrids to yield losses under adverse conditions.
Cuba’s urban organic gardens, called Organopónicos, provide most of the fresh vegetables to local communities. However, urban organic inputs can be contaminated by trace elements affecting human health. Scientists Alfaro et al. showed, indeed, that compost produced from municipal solid waste were largely contaminated by cadmium and lead. Because of this investigation, the use of municipal solid waste compost for food production has been forbidden in Cuba.
Participatory methods may increase the impact of agricultural research, but raise questions about scientific rigor. Scientists Steinke et al. show that involving high numbers of farmers can generate valid and meaningful results, which bring new opportunities in formal research, especially in remote locations or marginal environments.
Using plant residues as a mulch, modifies soil properties and enhances crop productivity potential under conservation agriculture. Scientists Ranaivoson et al. reviewed the benefits of mulch on soil water processes, soil erosion, soil nutrient supply, soil organic carbon, weed infestation and abundance of meso- and macrofauna. They showed evidence of improved performances with increasing amounts of surface crop residues.
Micro- and secondary nutrient deficiencies are widespread in sub-Saharan Africa. Scientists Kihara et al. reviewed the responses of crops such as maize, sorghum, wheat and rice to micro- and secondary nutrient applications in this region. They showed that both single and combined nutrient applications increased yields in a majority of cases. They discuss the need for amending the actual fertilizer blends accordingly.
Pollinator protection by farmers is currently based on rewards, which is unscalable for Low and Middle Income countries. Scientists Christmann et al. tested for the first time the new “farming with alternative pollinators” approach, which measures net income increase for farmers engaged in habitat enhancement (floral resources, nesting and hibernating sites, shelters against wind) for wild pollinators alternative to honeybees and commercial bumblebees. In Uzbekistan, they obtained a high income increase for field-crop cucumber and orchards of sour cherry.
Land use change from woody biomass to herbaceous species for bioenergy in marginal lands has an impact on soil organic carbon, which challenges the positive effect of fossil-C substitution. Scientists Nocentini and Monti showed that land use change from poplar to ten years of switchgrass and giant reed increased substantially and differently soil organic carbon stocks. These increases contributed significantly to life-cycle carbon savings of both perennial grass crops when biomass was used to produce advanced ethanol to supplant fossil fuels.
Farming system classifications into “conventional” vs. “organic”, “ecological”, “sustainable”, “agroecological”… deal in fact with a variety of farming practices and performances. Agronomists Therond et al. used environmental issues of industrial agriculture as a new attempt to sort out these farming systems. They identify six key agricultural models that promote greater sustainability and raise agronomic issues.