Micro-irrigation improves grain yield and resource use efficiency by co-locating the roots and N-fertilizer distribution of winter wheat in the North China Plain

作者:Li, Jinpeng; Xu, Xuexin; Lin, Gang; Wang, Yunqi; Liu, Yang; Zhang, Meng; Zhou, Jinyao; Wang, Zhimin*; Zhang, Yinghua*
来源:Science of the Total Environment, 2018, 643: 367-377.
DOI:10.1016/j.scitotenv.2018.06.157

摘要

Water use efficiency (WUE) and nitrogen fertilizer use efficiency (NUE) of winter wheat are urgently needed to further improve in the North China Plain (NCP). In this study, a 3-year field experiment was conducted during the 2014-2017 growing seasons to clarify the effect of traditional flood irrigation (TI), surface drip irrigation (DI), and micro-sprinkling irrigation (MSI) on grain yield, WUE, and NUE of winter wheat. Across the 3 years, grain yield of DI and MSI improved by 9.79% and 14.1%, WUE of DI and MSI increased by 12.3% and 17.7%, and NUE of DI and MSI increased by 9.77% and 14.0%, respectively compared with those of TI. Wheat subjected to the micro-irrigation treatments (DI and MSI) had higher chlorophyll content in flag leaves 10 days post-anthesis; this postponed senescence of the flag leaves, which increased dry matter accumulation post-anthesis, and increased 1000-grain weight and grain yield. The micro-irrigation treatments reduced pre-anthesis water consumption but increased post-anthesis water consumption and ensured the water supply in the top soil layer at the critical stage, thus increasing WUE. Root length density (RLD) of TI in the 0-80-cm soil layer was significantly higher than that of micro-irrigation, whereas micro-irrigation had higher RLD than TI below the 80-cm soil layer, which promoted the absorption and utilization of water and nitrogen in deep soil. The micro-irrigation treatments increased total nitrogen accumulation of the plants, reduced soil nitrate nitrogen (NO3--N) content at maturity, ensured the nitrogen supply in the top soil layer, thus increasing NUE. Overall, micro-irrigation with water and fertilizer as an integrated pattern significantly improved grain yield, WUE, and NUE of winter wheat in the NCP by co-locating the root, water, and N-fertilizer distribution and reducing NO3--N accumulation in deep soil. The best treatment was micro-sprinkling irrigation.