Dense planting and nitrogen fertilizer management improve drip-irrigated spring maize yield and nitrogen use efficiency in Northeast China

Abstract

Farmers in China often use nitrogen (N) fertilizers to ensure adequate crop growth. However, injudicious applications have increased the risk of environmental pollution, lower maize yields, and reduced profits for farmers. Appropriate N fertilizer management is crucial for improving yield and nitrogen use efficiency (NUE). This study conducted a three-year experiment involving nine N treatments (0, 45, 90, 135, 180, 225, 270, 315, and 360 kg ha-1) on a field under nitrogen fertilizer precision management (NFPM) in Northeast China. These results were compared with studies published within the past decade that analyzed yield and dry matter (DM) content under two management practices in Northeast China: conventional nitrogen fertilization management (CNFM) and water-saving fertilization management (WSFM). The findings reveal that maize yield increases with rising N application rates up to 270 kg ha-1, after which yield decreases. The kernel number (KN) and kernel weights (KW) of maize grown under NFPM were 13.7 and 14.7% higher than those grown under WSFM, respectively. Furthermore, they surpassed crops grown under CNFM by 38.4 and 21.2%, respectively. The maximum total yield of the NFPM treatment was 41.8 and 78.8% higher than WSFM and CNFM, respectively. Additionally, compared with CNFM and WSFM, NFPM significantly increased nitrogen use efficiency (NUE) across various N-level treatments. Optimizing nitrogen management could help farmers achieve higher yields and promote sustainable agricultural development.