Use of Controlled-Release Urea to Improve Yield, Nitrogen Utilization, and Economic Return and Reduce Nitrogen Loss in Wheat-Maize Crop Rotations

Excessive nitrogen (N) fertilizer input has become a common phenomenon among most farmers in the winter wheat–summer maize rotation system of north-central China, and resulted low nutrient use efficiency environmental pollution. Controlled-release urea (CRU) is proposed as solution to excessive fertilization because CRU achieves high yields reduces N losses. Therefore, mixed with normal at rates based on Nutrient Expert (NE) was used 4-year field experiment test preference crop yields, economic benefits, efficiencies, The following treatments were established: local farmers’ practices (FP); rate recommended by NE (NE); ratios 60:40 (CRU1) 75:25 (CRU2) system; 80% NE, CRU1 CRU2 (80%NE, 80%CRU1 80%CRU2). results showed that, compared treatment same application N, increased net benefits while reducing loss. 60% for 75% wheat had best overall effects. Compared FP, average grain yield, recovery 8.5%, 10.9% 11.3%, respectively, CRU1, 4.5%, 15.1% 10.3%, CRU2. Furthermore, significantly reduced loss from 38.5% 40.3% but soil NO3?-N NH4+-N contents 0–30 cm, although opposite (NO3?-N) observed deeper (30–90 cm). In 80%CRU2, yield equivalent those FP treatment, apparent reduced. Thus, these confirmed that combination China efficient valuable, potential improve benefit