Optimized fertilizer management to enhance yield of peanut by improving soil nutrients legacy in the wheat–peanut rotation system

Abstract Optimizing nitrogen (N) inputs to maximize legacy benefits and yield in wheat ( Triticum aestivum L.)–peanut ( Arachis hypogaea L.) rotation system remains challenging. A 2‐year field study evaluated effect of four fertilizer management strategies (T0: unfertilized control; T1: two‐split application, 150 kg N ha −1 at wheat sowing + top‐dressing 150 kg N ha −1 at jointing stage; T2: three‐split application and delaying N supply of wheat, 105 kg N ha −1 at wheat sowing + top‐dressing 105 kg N ha −1 at flag leaf stage + 90 kg N ha −1 at peanut sowing; T3: three‐split application and delaying N supply of wheat, 84 kg N ha −1 at wheat sowing + top‐dressing 84 kg N ha −1 at flag leaf stage + 72 kg N ha −1 at peanut sowing) on soil nutrients, photosynthetic performance, antioxidant capacity, nitrogen use efficiency (NUE), and yield of peanut in wheat–peanut rotation system. Results showed that T2 increased soil total nitrogen, available phosphorus, and available kalium during peanut growth season. T2 also increased the activity of superoxide dismutase, POD, and CAT, along with a reduction in malondialdehyde content of peanut. Additionally, T2 notably improved the leaf area index, SPAD (Soil and Plant Analysis Division) and photosynthetic rate. Relative to T1, T2 maintained wheat grain yield while increasing peanut N accumulation and pod N allocation, thereby achieving higher annual NUE and annual total yield. However, T3 used 20% less N than T2 and resulted in lower annual total yield than T2 but no significant difference with T1. Therefore, synergistic enhancement under T2 on soil nutrients, antioxidant capacity, and photosynthetic performance resulted in improved peanut pod yield and annual total NUE, representing an effective fertilizer management strategy for wheat–peanut rotation system in China.