Loaiza Sandra, Verchot Louis, Valencia Drochss, Costa Ciniro, Trujillo Catalina, Garcés Gabriel, Puentes Oscar, Ardila Jorge, Chirinda Ngonidzashe, Pittelkow Cameron
International Center for Tropical Agriculture (CIAT), Cali, Colombia; Omicas Program, Pontificia Universidad Javeriana sede Cali, Calle 18 No. 118-250, Cali, C.P, 760031, Colombia; Department of Plant Sciences, University of California, Davis One Shields Avenue, Davis, CA, 95616, USA.
International Center for Tropical Agriculture (CIAT), Cali, Colombia.
J Environ Manage. 2024 Dec;372:123376. doi: 10.1016/j.jenvman.2024.123376. Epub 2024 Nov 22.
Most of the research evaluating rice varieties, a major global staple food, for greenhouse gas (GHG) mitigation has been conducted under continuous flooding. However, intermittent irrigation practices are expanding across the globe to address water shortages, which could alter emissions of methane (CH) compared to nitrous oxide (NO) for reducing overall global warming potential (GWP). To develop climate-smart rice production systems, it is critical to identify rice varieties that simultaneously reduce CH and NO emissions while maintaining crop productivity under intermittent irrigation.
This study assessed CH and NO emissions, grain yield, and GWP of four rice varieties cultivated under intermittent irrigation in Colombia.
Four common commercial rice varieties were evaluated over two seasons-wet and dry in 2020 and 2021-in two Colombian regions (Tolima and Casanare).
Wet-season crop productivity was similar among varieties. However, F68 in Tolima and F-Itagua in Casanare significantly reduced yields in the dry season, likely due to periods of crop water stress. Overall, CH emissions and GWP were relatively low due to frequent field drainage events, with GWP ranging from 349 to 4704 kg CO equivalents ha. Accordingly, NO emissions contributed 73% to GWP across locations, as wet-dry cycles can increase NO emissions, creating a tradeoff for GWP when reducing CH through drainage. Varieties F67 in Tolima and F-Itagua in Casanare significantly reduced GWP by 32-61% across seasons, primarily by decreasing NO rather than CH emissions.
Rice varietal selection achieved significant GWP mitigation with limited impacts on grain yield, mainly due to reduced NO emissions under non-continuously flooded irrigation.
IMPLICATIONS/SIGNIFICANCE: This research underscores the critical role of rice varietal selection in addressing global climate-change and water-scarcity challenges, which drive the adoption of intermittent irrigation practices. By focusing on reducing N₂O emissions through appropriate variety selection, this study provides valuable insights for rice systems worldwide that are adapting to these pressing environmental challenges.
大多数评估作为全球主要主食的水稻品种温室气体减排效果的研究都是在持续淹水条件下进行的。然而，为应对水资源短缺问题，间歇性灌溉做法正在全球范围内推广，与一氧化二氮（N₂O）相比，这可能会改变甲烷（CH₄）的排放，从而降低全球变暖潜能值（GWP）。为了开发气候智能型水稻生产系统，关键在于识别出在间歇性灌溉条件下既能同时减少CH₄和N₂O排放又能保持作物产量的水稻品种。
本研究评估了在哥伦比亚间歇性灌溉条件下种植的四个水稻品种的CH₄和N₂O排放、谷物产量及GWP。
在2020年和2021年的两个季节（雨季和旱季），对哥伦比亚两个地区（托利马和卡萨纳雷）的四个常见商业水稻品种进行了评估。
各品种在雨季的作物生产力相似。然而，托利马地区的F68和卡萨纳雷地区的F-伊塔瓜在旱季产量显著降低，可能是由于作物遭受了水分胁迫期。总体而言，由于田间频繁排水，CH₄排放和GWP相对较低，GWP范围为349至4704千克二氧化碳当量/公顷。因此，N₂O排放在各地对GWP的贡献为73%，因为干湿循环会增加N₂O排放，在通过排水减少CH₄排放时会在GWP方面产生权衡。托利马地区的F67和卡萨纳雷地区的F-伊塔瓜在各季节显著降低了32%至61%的GWP，主要是通过减少N₂O而非CH₄排放。
水稻品种选择在显著降低GWP的同时对谷物产量影响有限，这主要归因于在非持续淹水灌溉条件下N₂O排放的减少。
启示/意义：本研究强调了水稻品种选择在应对全球气候变化和水资源短缺挑战方面的关键作用，这些挑战促使了间歇性灌溉做法的采用。通过专注于通过适当的品种选择减少N₂O排放，本研究为全球适应这些紧迫环境挑战的水稻系统提供了有价值的见解。
