Rotation of planting strips and reduction in nitrogen fertilizer application can reduce nitrogen loss and optimize its balance in maize-peanut intercropping

In dryland farming, maize (Zea mays L.) and peanut (Arachis hypogaea L.) intercropping has been widely prac-ticed to achieve sustainable agriculture goals. However, only a few studies have investigated the effect of reducing nitrogen (N) application on the performance of maize and peanut crops in intercropping system based on rotation of the planting strip. Therefore, a field study was conducted from 2018 to 2020 in Yangling, China, where the treatments comprised peanut monoculture, maize monoculture, maize-peanut intercropping, mai-ze-peanut rotational intercropping, and maize N reduction based on the rotational intercropping system. The N accumulation and yield in maize increased after intercropping, while the N accumulation, yield and N fixation capacity of peanut decreased than other treatments. In addition, soil residual N, ammonia volatilization, N leaching, and N2O emissions of maize-peanut intercropping significantly decreased than maize monoculture. The rotation of planting strips in maize-peanut intercropping had increased the land equivalent ratio by 3.06 % and 9.39 % and N recovery efficiency by 15.45 % and 27.37 % in the second and third years of planting, as well as alleviated the continuous cropping barrier for peanuts. N reduction does not affect N fixation capacity and yield of peanut and reduces ammonia volatilization and N leaching from farmland, although it does influence maize yield. The optimal cropping system was a 20 % N reduction in maize planting strip under rotational inter -cropping because N accumulation and the farmland productivity were not affected significantly, while the N losses to the environment also decreased by an average of 44.17 % and 14.87 % compared with traditional intercropping and monoculture in the second and third years of planting. These results are useful for optimizing cropping systems to promote sustainable development in dryland regions and mitigate N pollution.

Automated summary

The intercropping of maize and peanut in a rotational system with reduced nitrogen application showed positive effects on maize yield and nitrogen accumulation, while it resulted in decreased peanut yield and nitrogen fixation capacity. The intercropping system also reduced soil residual nitrogen, ammonia volatilization, nitrogen leaching, and N2O emissions. The rotation of planting strips improved land equivalent ratio and nitrogen recovery efficiency, as well as alleviated the continuous cropping barrier for peanuts.