Urban Cordeiro Emily, Arenas-Calle Laura, Woolf Dominic, Sherpa Sonam, Poonia Shishpal, Kritee Kritee, Dubey Rachana, Choudhary Amresh, Kumar Virender, McDonald Andrew
School of Integrative Plant Science, Soil and Crop Sciences, Cornell University, Bradfield Hall, Ithaca, NY, USA.
CIMMYT-India, Sabajpura, Khagaul, Patna, 801105, Bihar, India.
J Clean Prod. 2024 Jan 5;435:140240. doi: 10.1016/j.jclepro.2023.140240.
Crop residue burning is a common practice in many parts of the world that causes air pollution and greenhouse gas (GHG) emissions. Regenerative practices that return residues to the soil offer a 'no burn' pathway for addressing air pollution while building soil organic carbon (SOC). Nevertheless, GHG emissions in rice-based agricultural systems are complex and difficult to anticipate, particularly in production contexts with highly variable hydrologic conditions. Here we predict long-term net GHG fluxes for four rice residue management strategies in the context of rice-wheat cropping systems in Eastern India: burning, soil incorporation, livestock fodder, and biochar. Estimations were based on a combination of Tier 1, 2, and 3 modelling approaches, including 100-year DNDC simulations across three representative soil hydrologic categories (i.e., dry, median, and wet). Overall, residue burning resulted in total direct GHG fluxes of 2.5, 6.1, and 8.7 Mg CO-e in the dry, median, and wet hydrologic categories, respectively. Relative to emissions from burning (positive values indicate an increase) for the same dry to wet hydrologic categories, soil incorporation resulted in a -0.2, 1.8, or 3.1 Mg CO-e change in emissions whereas use of residues for livestock fodder increased emissions by 2.0, 2.1, or 2.3 Mg CO-e. Biochar reduced emissions relative to burning by 2.9 Mg CO-e in all hydrologic categories. This study showed that the production environment has a controlling effect on methane and, therefore, net GHG balance. For example, wetter sites had 2.8-4.0 times greater CH emissions, on average, than dry sites when rice residues were returned to the soil. To effectively mitigate burning without undermining climate change mitigation goals, our results suggest that geographically-target approaches should be used in the rice-based systems of Eastern India to incentivize the adoption of regenerative 'no burn' residue management practices.
作物秸秆焚烧是世界许多地区的常见做法，会造成空气污染和温室气体排放。将秸秆归还土壤的再生做法提供了一条“不焚烧”途径，既能解决空气污染问题，又能增加土壤有机碳。然而，水稻农业系统中的温室气体排放情况复杂且难以预测，特别是在水文条件高度变化的生产环境中。在此，我们预测了印度东部稻麦种植系统中四种水稻秸秆管理策略的长期净温室气体通量：焚烧、土壤掩埋、用作牲畜饲料和制成生物炭。估算基于一级、二级和三级建模方法的组合，包括对三种代表性土壤水文类别（即干燥、中等和湿润）进行的100年DNDC模拟。总体而言，在干燥、中等和湿润水文类别中，秸秆焚烧导致的直接温室气体总通量分别为2.5、6.1和8.7 Mg CO₂-e。相对于相同干燥至湿润水文类别下的焚烧排放（正值表示增加），土壤掩埋导致排放量变化为-0.2、1.8或3.1 Mg CO₂-e，而将秸秆用作牲畜饲料使排放量增加2.0、2.1或2.3 Mg CO₂-e。在所有水文类别中，生物炭相对于焚烧减少了2.9 Mg CO₂-e的排放。这项研究表明，生产环境对甲烷有控制作用，因此对净温室气体平衡也有控制作用。例如，当水稻秸秆归还土壤时，较湿润地区的CH₄排放量平均比干燥地区大2.8至4.0倍。为了在不损害减缓气候变化目标的情况下有效减少焚烧，我们的结果表明，在印度东部的水稻种植系统中应采用因地制宜的方法，以鼓励采用再生“不焚烧”的秸秆管理做法。
