Agro-Environmental Protection Institute Ministry of Agriculture and Rural Affairs, Tianjin, China.
PLoS One. 2020 Oct 29;15(10):e0241481. doi: 10.1371/journal.pone.0241481. eCollection 2020.
The application of controlled release urea (CRU) has been proposed as a crucial method to reduce the adverse environmental effects induced by conventional urea (CU). Yet, a systematic and quantitative analysis on how CRU affects staple crop production including wheat (Triticum aestivum L.), maize (Zea mays L.), and rice (Oryza sativa L.) is lacking. Here, a meta-analysis was conducted to determine how CRU influences soil chemical properties, total nitrogen (TN) uptake, grain yield, and nitrogen use efficiency (NUE) of staple crop in China. The results indicated that CRU application significantly increased soil organic carbon (SOC), TN, and available nitrogen (AN) by 5.93%, 3.89% and 13.98% respectively overall, while soil pH showed no significant changes. Compared to the application of CU, applying CRU significantly increased grain yield by 7.23%, which was mainly owing to the higher TN uptake (9.13%) across all the studies. In addition, the application of CRU significantly increased NUE, nitrogen agronomy efficiency (NAE), utilization rate of nitrogen fertilizer (NUR), and nitrogen physiological efficiency (NPE) by an average of 23.4%, 34.65%, 25.83% and 15.8% respectively which could be attributed to the slow nitrogen (N) release characteristics of CRU. The positive effect of CRU on grain yield and NUE of staple crop was greatest when the content of SOC and TN were extremely low, indicating that it was most effective to improve grain production of infertile soil by applying CRU. The finding of this study indicated that the application of CRU should be promoted for grain production, especially for infertile soil.
控释尿素（CRU）的应用被提议作为减少传统尿素（CU）引起的不利环境影响的关键方法。然而，缺乏关于 CRU 如何影响小麦（Triticum aestivum L.）、玉米（Zea mays L.）和水稻（Oryza sativa L.）等主要作物生产的系统和定量分析。在这里，进行了荟萃分析以确定 CRU 如何影响中国主要作物的土壤化学性质、总氮（TN）吸收、籽粒产量和氮利用效率（NUE）。结果表明，CRU 应用总体上分别显著增加了 5.93%、3.89%和 13.98%的土壤有机碳（SOC）、TN 和有效氮（AN），而土壤 pH 没有显著变化。与 CU 的应用相比，CRU 的应用显著增加了 7.23%的籽粒产量，这主要是由于所有研究中 TN 吸收增加了 9.13%。此外，CRU 的应用平均显著增加了 23.4%、34.65%、25.83%和 15.8%的 NUE、氮农学效率（NAE）、氮肥利用率（NUR）和氮生理效率（NPE），这可以归因于 CRU 的缓慢氮（N）释放特性。当 SOC 和 TN 含量极低时，CRU 对主要作物籽粒产量和 NUE 的积极影响最大，这表明通过应用 CRU 提高瘠土的粮食产量最有效。本研究的结果表明，应推广 CRU 的应用以促进粮食生产，特别是在瘠土上。
