The Rice Research Institute of Guangdong Academy of Agricultural Sciences/Guangdong Key Laboratory of New Technology for Rice Breeding, Guangzhou 510640, China.
The Rice Research Institute of Guangdong Academy of Agricultural Sciences/Guangdong Key Laboratory of New Technology for Rice Breeding, Guangzhou 510640, China.
Sci Total Environ. 2017 Dec 31;609:46-57. doi: 10.1016/j.scitotenv.2017.07.118. Epub 2017 Jul 19.
Nitrogen non-point pollution and greenhouse gas (GHG) emission are major challenges in rice production. This study examined options for both economic and environmental sustainability through optimizing water and N management. Field experiments were conducted to examine the crop yields, N use efficiency (NUE), greenhouse gas emissions, N losses under different N and water management. There were four treatments: zero N input with farmer's water management (N0), farmer's N and water management (FP), optimized N management with farmer's water management (OPT) and optimized N management with alternate wetting and drying irrigation (OPT+AWD). Grain yields in OPT and OPT+AWD treatments increased by 13.0-17.3% compared with FP. Ammonia volatilization (AV) was the primary pathway for N loss for all treatments and accounted for over 50% of the total losses. N losses mainly occurred before mid-tillering. N losses through AV, leaching and surface runoff in OPT were reduced by 18.9-51.6% compared with FP. OPT+AWD further reduced N losses from surface runoff and leaching by 39.1% and 6.2% in early rice season, and by 46.7% and 23.5% in late rice season, respectively, compared with OPT. The CH emissions in OPT+AWD were 20.4-45.4% lower than in OPT and FP. Total global warming potential of CH and NO was the lowest in OPT+AWD. On-farm comparison confirmed that N loss through runoff in OPT+AWD was reduced by over 40% as compared with FP. OPT and OPT+AWD significantly increased grain yield by 6.7-13.9%. These results indicated that optimizing water and N management can be a simple and effective approach for enhancing yield with reduced environmental footprints.
氮非点源污染和温室气体（GHG）排放是水稻生产面临的主要挑战。本研究通过优化水氮管理，探讨了经济和环境可持续性的选择。田间试验研究了不同氮、水管理下作物产量、氮利用效率（NUE）、温室气体排放和氮素损失。处理措施包括：不施氮并采用农民传统管理方式（N0）、农民常规氮和水管理（FP）、优化氮管理并采用农民传统水管理（OPT）和优化氮管理并采用交替湿润和干燥灌溉（OPT+AWD）。与 FP 相比，OPT 和 OPT+AWD 处理的籽粒产量分别提高了 13.0-17.3%。氨挥发（AV）是所有处理措施中氮素损失的主要途径，占总损失的 50%以上。氮素损失主要发生在分蘖前期。与 FP 相比，OPT 处理减少了 AV、淋溶和地表径流导致的氮素损失，分别减少了 18.9-51.6%。在早稻季，OPT+AWD 进一步减少了氮素通过地表径流和淋溶的损失，分别减少了 39.1%和 6.2%，在晚稻季，分别减少了 46.7%和 23.5%，而 OPT 处理的 CH 排放比 OPT 和 FP 低 20.4-45.4%。CH 和 NO 的总全球变暖潜势在 OPT+AWD 中最低。田间比较证实，与 FP 相比，OPT+AWD 中氮素通过地表径流的损失减少了 40%以上。OPT 和 OPT+AWD 显著提高了 6.7-13.9%的籽粒产量。这些结果表明，优化水氮管理可以是一种简单有效的方法，在减少环境足迹的同时提高产量。
