Soil Biology Group, Wageningen University, Droevendaalsesteeg 3, PO Box 47, 6700 AA Wageningen, the Netherlands; Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark; International Rice Research Institute (IRRI), Los Baños, the Philippines.
International Rice Research Institute (IRRI), Los Baños, the Philippines.
Sci Total Environ. 2020 Oct 15;739:140215. doi: 10.1016/j.scitotenv.2020.140215. Epub 2020 Jun 15.
Rice production systems are the largest anthropogenic wetlands on earth and feed more than half of the world's population. However, they are also a major source of global anthropogenic greenhouse gas (GHG) emissions. Several agronomic strategies have been proposed to improve water-use efficiency and reduce GHG emissions. The aim of this study was to evaluate the impact of water-saving irrigation (alternate wetting and drying (AWD) vs. soil water potential (SWP)), contrasting land establishment (puddling vs. reduced tillage) and fertiliser application methods (broadcast vs. liquid fertilisation) on water-use efficiency, GHG emissions and rice yield. The experiment was laid out in a randomised complete block design with eight treatments (all combinations of the three factors) and four replicates. AWD combined with broadcasting fertilisation was superior to SWP in terms of maintaining yield. However, seasonal nitrous oxide (NO) emissions were significantly reduced by 64% and 66% in the Broadcast-SWP and Liquid fertiliser-SWP treatments, respectively, compared to corresponding treatments in AWD. The SWP also significantly reduced seasonal methane (CH) emissions by 34 and 30% in the broadcast and liquid fertilisation treatments, respectively. Area-scaled GWPs were reduced by 48% and 54% in Broadcast-SWP and Liquid fertiliser-SWP treatments respectively compared to the corresponding treatments in AWD. Compared to AWD, the broadcast and liquid fertilisation in SWP irrigation treatments reduced yield-scaled GWPs by 46% and 37%, respectively. In terms of suitability, based on yield-scaled GWPs, the treatments can be ordered as follows: Broadcast-SWP < Broadcast-AWD = Liquid fertiliser-SWP < Liquid fertiliser-AWD. Growing-season water use was 15% lower in the SWP treatments compared with the water-saving AWD. Reduced tillage reduced additional water use during land preparation. The conclusions of this study are that improved water management and timely coordination of N fertiliser with crop demand can reduce water use, N loss via NO emissions, and CH emissions.
水稻生产系统是地球上最大的人为湿地，为全球一半以上的人口提供食物。然而，它们也是全球人为温室气体（GHG）排放的主要来源。已经提出了几种农业策略来提高水利用效率并减少 GHG 排放。本研究的目的是评估节水灌溉（交替湿润和干燥（AWD）与土壤水势（SWP））、不同土地建立（耕耙与少耕）和施肥方法（撒播与液体施肥）对水利用效率、GHG 排放和水稻产量的影响。该实验采用随机完全区组设计，设 8 个处理（三个因素的所有组合），重复 4 次。与 SWP 相比，AWD 结合撒播施肥在保持产量方面更具优势。然而，与 AWD 相比，在 Broadcast-SWP 和 Liquid fertiliser-SWP 处理中，季节性氧化亚氮（NO）排放分别显著减少了 64%和 66%。SWP 还分别显著减少了Broadcast 和 Liquid fertiliser 处理中季节性甲烷（CH）排放 34%和 30%。与 AWD 相比，在 Broadcast-SWP 和 Liquid fertiliser-SWP 处理中，面积标准化全球升温潜势（GWP）分别减少了 48%和 54%。与 AWD 相比，SWP 灌溉处理中的撒播和液体施肥分别将产量标准化 GWP 减少了 46%和 37%。就适用性而言，基于产量标准化 GWP，处理可以按以下顺序排列：Broadcast-SWP<Broadcast-AWD=Liquid fertiliser-SWP<Liquid fertiliser-AWD。与节水的 AWD 相比，SWP 处理的生长季用水量减少了 15%。少耕减少了土地准备期间的额外用水量。本研究的结论是，改善水管理和及时协调作物需求的氮肥可以减少水的使用、通过 NO 排放的氮损失和 CH 排放。
