Integrated management for sustainable cropping systems: looking beyond the greenhouse balance at the field scale

Cover crops (CC) promote the accumulation of soil organic carbon (SOC) which provides multiple benefits to agroecosystems. However, the additional nitrogen (N) inputs into the soil could largely offset the CO2 mitigation potential due to the increasing N2O emissions. Integrated management adapts to the site-specific characteristics and encompasses the use of organic and synthetic fertilizers to maximize yields and minimize impacts by using a strategy of crop sequencing adapted to local conditions. The goal of this work was to test if integrated management, centered on CC adoption, has the potential of maximizing SOC without increasing the soil greenhouse gas (GHG) net flux and other agro-environmental impacts such as nitrate leaching. To this purpose, we ran the DayCent biochemistry model on approximately 8000 soil sampling locations in the European Union. We found that by adapting simple strategies of crop sequencing to local conditions, such as switching from legume to grass CC when the GHG flux was positive (source), soil N2O emissions could be greatly limited. Additional reductions of synthetic fertilizers applications are possible through better accounting for N available in green manures and from mineralization of soil reservoirs, while maintaining cash crop yields. Therefore, our results suggest that a CC integrated management can maximize the agro-environmental performance of cropping systems while reducing environmental trade-offs.

QUEMADA Miguel;  LASSALETTA Luis;  LEIP Adrian;  JONES Arwyn;  LUGATO Emanuele; 

2020-04-03

WILEY

JRC117163

1354-1013 (online),   

https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.14989,    https://publications.jrc.ec.europa.eu/repository/handle/JRC117163,   

10.1111/gcb.14989 (online),