Optimizing Water and Nitrogen Management for Green Pepper (Capsicum annuum L.) under Drip Irrigation in Sub-Tropical Monsoon Climate Regions

Green pepper (Capsicum annuum L.) is one of the major vegetables cultivated in sub-tropical monsoon climate regions. However, with unreasonable use water and nitrogen (N) fertilizer, efficient N fertilizer management systems need to be identified. The goal this project was investigate coupling effects different amounts on green yield, efficiency (WUE), as well (NUE) optimum combination inputs determined for multi-objective optimization through multiple regression analysis combinations likelihood functions. pot experiment conducted during growing seasons (May–September) 2019 2020 a greenhouse at Nanchang, Jiangxi China that included three deficit levels, i.e., mild (W1: 95~80%θFC, %θ field capacity simplified %θFC), moderate (W2: 80~65%θFC), severe (W3: 65~50%θFC), four levels application (Napp) rate, 6.0 (N1), 3.0 (N2), 1.5 (N3), 0.0 g plant−1 (N4), total twelve treatments (i.e., 3 × 4) six replications. Results show have an extremely significant effect (p < 0.01) yield WUE, but no NUE > 0.05). NUE. Meanwhile, treatment interaction WUE were 0.01), varied between two years. maximum yields (576.26 619.00 plant−1) occurred when level Napp rate 80~65%θFC plant−1. While plant−1, WUEs NUEs reached maximum, which 20.14 17.71 L−1, 76.54, 77.73 g−1 2020. dualistic quadric equations irrigation amount indicated cannot reach same time. By establishing multiobjective model using functions, it concluded shall controlled 3.78 can used suitable strategy comprehensive benefits pepper. obtained provide scientific basis fertilization