Study on the effectiveness and mechanism of a sustainable dual slow-release model to improve N utilization efficiency and reduce N pollution in black soil

• Published in: The Science of the total environment 2024-01, Vol.907, p.168033, Article 168033
• Main Authors: Wang, Gaoxu, Gou, Zechang, Tian, Geng, Sima, Wenyue, Zhou, Jiafeng, Bo, Zhenghao, Zhang, Zhongqing, Gao, Qiang
• Format: Article
• Language: English
• Subjects: Agriculture; Ammonium Compounds; Black soil area; Dual slow-release model; Fertilizers - analysis; N2O emission; Nitrates; Nitrogen - analysis; Nitrous Oxide - analysis; NO3− leaching; NUE; Soil; Urea
• ISSN: 0048-9697; 1879-1026; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.168033

Long-term intensive cultivation has led to serious N loss and low N fertilizer utilization efficiency (NUE) in black soil areas. The lost N is not only a waste of resources but also a serious pollution threat to the environment, leading to the decline in water quality and food safety and the greenhouse effect. In the present study, a stable dual slow-release model, CPCS-Urea, was prepared by in situ polymerization using nitrapyrin, urea and melamine-formaldehyde resin as raw materials. The effect of the dual slow-release model was systematically evaluated using two consecutive years of field experiments. Five treatments were established in the field experiment: no N fertilizer (N0), urea (N180), 1 % CPEC-Urea, 0.5 % CPCS-Urea, and 1 % CPCS-Urea. The results showed that the new dual slow-release CPCS-Urea model outperformed both the use of urea and the traditional slow-release CPEC-Urea model in reducing N losses and improving NUE. The application of CPCS-Urea reduced nitrate (NO3−) leaching by 28.2 %–47.2 % and N2O emissions by 36.5 %–42.4 % and increased NUE by 20.7 %–28.5 % compared to urea application. The CPCS-Urea model modulated the activity of ammonia-oxidizing bacteria (AOB) and dissimilatory nitrate reduction to ammonium (DNRA) bacteria in soil, showing a significant decrease in AOB activity and an increase in DNRA activity. This results in a lower soil NO3−-N yield and a 53.1 %–72.0 % increase in NH4+-N content, providing sufficient N for the entire growth and development cycle of maize. In short, the dual slow-release CPCS-Urea model has great application prospects for promoting agricultural development in black soil areas. [Display omitted] •Dual slow-release model (CPCS-Urea) can effectively reduce N pollution and improve NUE.•CPCS-Urea can increase NUE by 20.7 %–28.5 % and reduce N2O emissions by 36.5 %–42.4 %.•CPCS-Urea reduces the conversion of ammonium nitrogen to nitrate nitrogen by inhibiting AOB activity and activating DNRA activity for a long time.