It is a challenge to understand how on-farm diversity can be mobilized to design sustainable agricultural systems. Scientists Lurette et al. used a model to represents the diversity in the organization of several farms composing a territory in the South of France. They showed how diversity impacted farm performances, and how external inputs or subsidies impacted their sustainability. Pairing territory composition diversity with on-farm diversity will help in designing sustainable agricultural systems.
Diversification of cropping systems is a major way towards sustainable agriculture. Scientists Martin et al. recently reviewed the impacts of integrating ley pastures in cropping systems. Such pastures provide farmers with a wide range of services, including soil conservation, nutrient provision and recycling, soil water retention, and biological control of pests and weeds. Lay pastures contribute also other services to the society, such as water purification, climate regulation, habitat provision for conserving associated biodiversity, and forage production.
Millions of hillside farmers around the world cultivate crops on narrow terraces, whose walls are often underutilized. Scientists Chapagrain et al. recently showed that cultivation of wall-climbing crops (e.g. chayote squash, pumpkin, yam) and wall-descending crops (e.g. ricebean, cowpea, horsegram, blackgram) can enhance economic returns to farmers. The adoption of this promising practice can improve the ecosystems and the well-being of terrace farmers.
Mobile apps are available for agriculture but very few are designed to help farmers connect to information on environmental, social, and economic sustainability concerns beyond the field or farm. Scientists Eichler et al. reviewed existing web-based and mobile apps for agriculture decision support. They highlight a need for apps that improve multi-directional knowledge sharing through sensor, satellite, and farmer networking.
Maximizing crop production while improving soil carbon storage and nitrogen-use efficiency is a major challenge in the sustainable intensification of agro-ecosystems. Agronomists Castelli et. al. compared four arable systems and a no-till permanent meadow during a 30 year field experiment. All ecosystems caused clear trade-offs between services. Both the no-till permanent meadow and the most productive annual rotation lead to win-lose solutions. Farmers, however, may justify high fertilization practices if their management goal is to spare land for less intensive uses such as permanent meadow.
Ethiopia faces high risk of soil carbon depletion largely due to deforestation and continuous cultivation. Deforestation has resulted in losses of between 20 and 50 percent of the soil carbon stocks in the first meter of the soil depth. Scientists Berihu et al. studied the effect of land use-land cover changes on soil organic carbon and nitrogen. They found that the soil organic carbon sequestration and total nitrogen content for dense forest were significantly higher than that of grassland, open forest, and farm land. Conversion of forest to other land use may lead to massive losses in soil nutrients.
Tropical deforestation for grass plantations for livestock production is responsible for about 30% of CO2 emissions. Life fencing, which is the use of trees for fences, may help to decrease and balance CO2 emissions. Villanueva-López et al. studied the impact of live fences of Gliricidia Sepium trees in livestock systems on soil CO2 emissions. They found that CO2 emissions did not differ with or without tree fences, but they also evidenced that tree fences reduced the diurnal and seasonal variability of soil CO2 emissions.
Drylands turn rapidly into bare deserts if soil carbon is not correctly managed. Indeed soil carbon has many beneficial properties such as water holding, plant nutrient storage and glueing the minerals to prevent erosion. In addition storing more carbon in drylands would slow down global warming. Plaza-Bonilla et al. review the management of organic and inorganic carbon in drylands.
Crop-damaging wireworms are the soil-dwelling larvae of click beetles. Wireworms have emerged in Europe over the last 15 years. There is actually few efficient control solutions, and actual control options use toxic pesticides. There is therefore a need for safer control techniques. A survey of 341 maize fields by Saussure et al. shows that wireworm damage is decreased by the occurrence of hedges and cultivated crops at the maize field border. Whereas wireworm damage is increased by the occurrence of grassland at the maize field border or during the rotation.
Agriculture provides society with many services such as food, carbon sequestration, pest regulation and jobs. The efficiency of those services depends on managament choices by farmers at the landscape scale. Chopin et al. designed a new method to study the evolution of farming systems at the landscape scale.