Recently, the Innovation Team of Saline-alkali Soils Amelioration at the Institute of Agricultural Resources and Regional Planning (IARRP) of the Chinese Academy of Agricultural Sciences (CAAS) systematically analyzed the long-term sequential changes in crop yields under conservation tillage, revealing the role of rational nitrogen fertilization in improving soil quality and productivity. These findings, titled "Long-term nitrogen fertilization enhances crop yield potential in no-tillage systems through enhancing soil fertility", were published in the prestigious journal "Resources, Conservation & Recycling" (IF = 13.2).

Conservation tillage, as a sustainable agricultural practice to mitigate soil degradation and climate change risks, has garnered widespread attention. Nevertheless, variables such as precipitation and temperature have been found to diminish crop yields in no-tillage systems. Previous studies indicates that elevated nitrogen fertilization can alleviate this yield reduction; however, the efficacy of sustained, judicious nitrogen fertilization in augmenting no-tillage yields to potentially surpass traditional tillage productivity by improving soil quality remains uncertain.

An 18-year field experiment was conducted to the synergistic effects of tillage practices and nitrogen fertilization on crop yields, yield stability, soil quality, and net profits. The results indicated that rational nitrogen fertilization (below the national average per acre) positively influenced yield in no-tillage systems, leading to a 28.9% increase in wet years and a 14.7% increase in dry years. Furthermore, extending the duration of no-tillage practices further amplified the beneficial effects of nitrogen fertilization on crops yields. As the duration of no-tillage increased, the rate of yield increase from nitrogen fertilization also increased, varying between 8.2% and 24.5% over the 18-year period. This was mainly attributed to the improvement in soil quality under no-tillage conditions with rationally increased nitrogen application, particularly the significant enhancement of soil organic carbon, available nitrogen, and phosphorus.

This study further clarifies that advocating for no-tillage practices and rational nitrogen fertilization is an effective approach to address the issues of excessive nitrogen fertilizer application and food security in China. It offers substantial technical and theoretical support for enhancing crop yields and land quality.

Dr. Shengping Li from IARRP is the first author of the paper, with Dr. Xueping Wu as the corresponding author. Funding for this study wsa provided by the National Natural Science Foundation of China and the Chinese Academy of Agricultural Sciences' Science and Technology Innovation Project.