Frontiers of Agricultural Science and Engineering2021,8 (1):148-158
On the cover
Crop and animal production systems produce >95% of all the food consumed in the world, in coexistence with natural and urban environments. The cover image visualizes the coupling of crop and animal production systems through the exchange of animal feed and animal manure (indicated by the outside arrows). However, the current situation is often much less romantic than suggested by the image. Crop and animal production systems have become more specialized and spatially decoupled during last decades. This has been economically attractive, but resource use efficiency, nutrient recycling and resilience to external shocks of the systems have decreased. As a result, it is increasingly believed that a tighter spatial (re)coupling of crop and animal production systems is needed for Agriculture Green Development. A tighter spatial coupling of crop and animal production will facilitate the exchange of feed and manure, will reduce the need for synthetic fertilizers in crop production, will improve soil fertility, and will reduce the environmental cost of food production.