Reducing fertilization with high planting density increases maize yield stability and nitrogen use efficiency in semi-arid areas

High-density planting is a vital cultivation measure to improve crop yield. In the semi-arid region, insufficient precipitation and high variability are the primary factors that restrict agricultural development. Matching planting density and fertilizer application with precipitation is a promising technical strategy to ensure yield stability and enhance nitrogen (N) use efficiency (NUE). To achieve this objective, we conducted a continuous field experiment in the Loess Plateau region of Northwest China between 2015 and 2020. Under conventional (CF) and reduced fertilization (RF, 20 % CF) conditions, we investigated the response characteristics of dry matter accumulation, yield, yield components, NUE, N surplus, and net income of maize as the density increased from 5.25 (D1) to 6.75 (D2), 8.25 (D3), and 9.75 (D4) x 104 plants ha- 1. The results indicated that reduced fertilizer application led to a decrease in grain yield by 6.2-8.7 %, whereas increasing the density by at least 1.50 x 104 plants ha- 1 (D2) could compensate for the yield reduction caused by reduced fertilization (N 55 + P2O5 27 kg ha- 1) in normal and wet years. The compensatory effect initially increased and then decreased as the density increased, with the highest yield observed at planting density D3. By increasing the rapid growth rate of maize (6.3-17.1 %) and extending the rapid growth duration (0.9-2.5 days) through high planting density, reduced fertilization combined with high-density planting (RF.D3) significantly increased the cumulative yield, yield stability, net income, and NUE was by 9.4 %, 18.9 %, 10.6 %, and 37.0 %, respectively, over six years, compared with CF.D1 treatment. Additionally, the N surplus was reduced by 44.6 %. In conclusion, using reduced fertilization with high planting density measures can achieve yield stability and sustainable maize production in semi-arid areas.