National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, National Engineering & Technology Research Center for Slow and Controlled Release Fertilizers, College of Resources and Environment, Shandong Agricultural University, Taian, Shandong 271018, China.
National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, National Engineering & Technology Research Center for Slow and Controlled Release Fertilizers, College of Resources and Environment, Shandong Agricultural University, Taian, Shandong 271018, China; Department of Soil and Water Sciences, Tropical Research and Education Center, IFAS, University of Florida, Homestead, FL 33031, USA.
J Environ Manage. 2018 Aug 15;220:191-197. doi: 10.1016/j.jenvman.2018.05.010. Epub 2018 May 26.
The use of controlled-release urea (CRU) has become one of best management practices for increasing crop yield and improving nitrogen (N) use efficiency (NUE). However, the effects of CRU on direct-seeded rice are not well understood while direct-seeding has gradually replaced transplanting due to increasing labor cost and lack of irrigation water. The objective of this two-year field experiment was to compare the effects of the CRU at four rates (120, 180, 240 and 360 kg N ha, CRU1, CRU2, CRU3 and CRU4, respectively) with a conventional urea fertilizer (360 kg N ha; U) and a control (no N fertilizer applied; CK) on yield, biomass, NUE of direct-seeded rice and soil nutrients. The results indicated that the successive release rates of N from CRU corresponded well to the N requirements of rice. The use of CRU3 and CRU4 increased rice grain yields by 20.8 and 28.7%, respectively, compared with U. In addition, the NUEs were improved by all CRU treatments compared to the U treatment. Concentrations of NO-N and NH-N in the soil were increased, especially during the later growth stages of the rice, and the leaching of N was reduced with CRU treatments. In conclusion, applying CRU on direct-seeded rice increased the crops yields and NUE, increased nitrogen availability at the late growth stages, and reduced N leaching.
控释尿素（CRU）的使用已成为提高作物产量和提高氮（N）利用效率（NUE）的最佳管理实践之一。然而，由于劳动力成本增加和灌溉用水缺乏，直播已逐渐取代移栽，而控释尿素对直播水稻的影响尚不清楚。本两年田间试验的目的是比较四种施用量（120、180、240 和 360 kg N ha，分别为 CRU1、CRU2、CRU3 和 CRU4）的控释尿素与常规尿素肥料（360 kg N ha；U）和对照（不施氮肥；CK）对直播水稻产量、生物量、NUE 和土壤养分的影响。结果表明，控释尿素的连续释放率与水稻的氮需求很好地吻合。与 U 相比，CRU3 和 CRU4 分别使水稻籽粒产量增加了 20.8%和 28.7%。此外，与 U 处理相比，所有控释尿素处理均提高了 NUE。土壤中硝态氮（NO-N）和氨态氮（NH-N）的浓度增加，尤其是在水稻后期生长阶段，氮的淋失减少。总之，在直播水稻上施用控释尿素可以提高作物产量和 NUE，增加后期生长阶段的氮素有效性，并减少氮淋失。
