Urban farms can have positive social and ecological impacts on cities but their economic viability is a burning issue. Scientists Chang and Morel explored the economic viability of organic vegetables microfarms in London. Although specific strategies at the farm level can increase the economic success of urban farms, engagement with the wider political context is needed to support the development of urban agriculture.
Spatial quantification and mapping of the supply and demand of crops is helpful to plan local agriculture and make decisions. Scientists Sahle et al. quantified and mapped in Ethiopia the supply and demand of kocho, an indigenous food cooked from the Enset crop. In order to ensure food security of local communities, planners and decision-makers may now use such information to improve crop production in areas where the current supply-demand is not balanced so as to improve Enset access to local market.
Arable soils tend to lose organic carbon in the Mexico áreas cultivated with maize. Scientists De León-González et al. studied the emissions of C-CO2 and soil organic carbon in a highland of central Mexico under different agricultural systems. They found that cultivation of perennial cactus crop in combination with maize production allows maintaining soil fertility, due to cactus crop root characteristics.
Sustainable crop production requires the efficient use of agronomic inputs in order to increase yield without causing a negative environmental impact. In such a context, the choice of the crop succession influences the amount of fertilizers used. Scientists Jacobs et al. studied the preceding crop effects on input efficiency for sugar beet cultivation. They propose a method to assess these effects, for decision makers.
Changes in land management pattern, such as the way that grazing is organized, affect soil fertility. Scientists Cao et al. studied the soil fertility in the Qinghai-Tibetan Plateau. They observed that lands owned and managed by single families had their soils more severely degraded than those of lands collaboratively managed by multiple families.
Mixed farming systems represent the most common form of agriculture worldwide. The agroecological performance of these systems is strongly determined by practices improving the integration between crop and livestock productions. Agronomists Stark et al. showed that by looping nutrient cycles, these farming systems would be more efficient and more resilient to meet the challenges of agroecology.
The integration of animals into crop systems has many potential benefits. Scientists Niles et al. studied the integration of sheep into New Zealand viticulture. Farmers who have implemented this novel practice perceived significant benefits such as fewer herbicide applications and fewer mows. Implemented at a wider scale, it could provide greater ecological and profits than current conventional practices.
Producing edible biomass on rooftops is a growing worldwide demand of large urban areas. Scientists Grard et al. achieved for the first time a quantitative assessment of several ecosystem services delivered by a productive green roof based on urban wastes. They show that low-tech productive rooftops, particularly easy to manage, allow the recycling of organic wastes and the production of vegetables by using rainwater but no chemical fertilizer.
The effective management of fruit fly and other pests of national significance requires cooperation between farmers, communities and industries. Scientists Mankad et al studied the potential barriers and facilitators for adoption of innovative practices able to reduce biosecurity risks. They also explored social attitudes towards the use of novel sterile insect technology. This is a worldwide topical discussion, as nations should prepare for managing increased biological and agricultural risks due to rising international trade.
The twin challenges of climate change and food security call for climate-smart agriculture, that is to say agriculture that helps to mitigate and adapt to climate change. Scientists Scherer and Verburg review the potentials and trade-offs of climate-smart agricultural measures taken by producers and consumers, and identify their linkages. They advocate not solely focusing research and implementation on one-sided measures but designing good, site-specific combinations of both demand- and supply-side measures to use the potential of climate-smart agriculture more effectively.