Nitrogen (N) fertilization is an effective way to ensuring food security. However, fertilizer-N losses through leaching and gaseous emission may contribute to severe ecological and environmental problems. Quantifying the fate of fertilizer N is pivotal for local agricultural management.
Conservation tillage, typically characterized by continuous minimum mechanical disturbance (e.g., no-tillage) and at least 30% of permanent soil organic cover with crop residues, have been widely proposed to improve the quality of cultivated land. Changes in soil micro-environment due to application of maize straw mulching and inhibitor could affect soil N dynamics and subsequently fertilizer N fate.
Based on a continuous 9-year no-tillage farmland, a research team from the Institute of Applied Ecology of the Chinese Academy of Sciences (CAS) conducted an in-situ 15N-labeled micro-plot to investigate the transformation characteristics and fate of fertilizer N in soil-crop system in response to maize straw mulching and inhibitor application.
The results indicated that maize straw mulching and inhibitor application can effectively guarantee soil N retention and synchronism N supply with crop demand by regulating the fertilizer N conversion process between fixed NH4+ and organic N pools during different growing stages of maize, which is conducive to maintain high crop yield, improve fertilizer N use efficiency, decrease fertilizer N input and reduce environmental problems caused by fertilizer N loss. Meanwhile, soil N pool is the main source of N uptake by crop. Maize straw mulching is beneficial for fertilizing the soil and ensuring its continuous N supply capacity. Therefore, maize straw mulching alone and its combination with inhibitor have a good application prospect in alleviating the degradation of black soil in Northeast China and promoting the sustainable development of local agriculture.
These findings were published in Agriculture Ecosystems & Environment entitled “Stover mulching and inhibitor application maintain crop yield and decrease fertilizer N input and losses in no-till cropping systems in Northeast China”.
It was supported by the National Natural Science Foundation of China.
Institute of Applied Ecology, Chinese Academy of Sciences