Long-term nitrogen fertilization enhances crop yield potential in no-tillage systems through enhancing soil fertility

Nitrogen addition can weaken yield reduction under no-tillage, a fundamental component of conservation tillage. However, the potential long-term benefits of nitrogen addition in enhancing the yield capacity of no-tillage by improving soil quality remain uncertain. Here we investigated the effects of tillage and nitrogen addition on both yield and soil quality through a comprehensive long-term experiment. We found that increased nitrogen inputs resulted in higher yield under no-tillage, particularly in wet years. Over an 18-year period, the rate of yield enhancement attributed to nitrogen addition varied from 8.2 % to 24.5 %, resulting in the most optimal yield under no-tillage with adequate nitrogen addition. Similarly, soil quality of no-tillage exhibited improvement with nitrogen inputs, especially in terms of organic carbon and the availability of nitrogen and phosphorus, thereby enhancing production potential. This study concluded that adequate nitrogen addition further improved both crop production and the sustainability of no-tillage systems.