Effects of water and nitrogen regulation on water consumption characteristics and yield of eggplant in a cold and arid oasis region of Northwest China

Abstract

This study conducted a one-year field experiment to investigate the impacts of different water and nitrogen application strategies on the water consumption characteristics, yield, and WUE of eggplants in the cold and arid regions of Northwest China. The experiment included three irrigation levels (50-60%, 60-70%, and 70-80% of field capacity) and three nitrogen application levels (215 kg/ha, 270 kg/ha, and 325 kg/ha).The results demonstrated that both irrigation and nitrogen application significantly influenced the water consumption characteristics, WUE, and yield of eggplants. Increasing irrigation levels led to a significant rise in water consumption, particularly under high nitrogen conditions. Mild water deficit significantly enhanced WUE and yield while reducing resource input. Moderate nitrogen application promoted yield increases, whereas excessive nitrogen had no significant positive effect on yield and could even have negative consequences. These findings provide a theoretical foundation for optimizing water and nitrogen management in eggplant cultivation in arid regions of Northwest China, especially in improving yield and resource use efficiency.