College of Agronomy and Biotechnology, Southwest University, Chongqing, 400715, China.
College of Resources and Environment, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China.
Environ Sci Pollut Res Int. 2022 Mar;29(12):17787-17798. doi: 10.1007/s11356-021-16990-w. Epub 2021 Oct 21.
Although hybrid maize seed production is one of the most important agriculture systems worldwide, its greenhouse gas (GHG) emissions and potential mitigation measures have not been studied. In this study, we used life cycle assessment (LCA) to quantify the GHG emissions of 150 farmers run by 6 companies in an area of northwest China known for hybrid maize seed production. The results indicated that the average reactive nitrogen (Nr) losses and GHG emissions from hybrid maize seed production were 53 kg N ha and 8077 kg CO eq ha, respectively. Furthermore, the average nitrogen and carbon footprints of the process were 12.2 kg N Mg and 1495 kg CO eq Mg, respectively. Nitrogen fertilizer and electricity consumption for irrigation were the main contributors to high GHG emissions, accounting for 60% and 30% of the total, respectively. The GHG emissions from seed production for different companies varied greatly with their resource input. There was also a large variation in environmental burdens among the 150 farmers. Based on an analysis of the yield group, we found that the carbon footprint of the first group (the one with the highest yield) was 27% lower than the overall average. Scenario analysis suggests that a combined reduction of N input rate, optimizing irrigation, and increasing yield can eventually mitigate the carbon footprint of hybrid maize seed production by 37%. An integrated systematic approach (e.g., ISSM: integrated soil-crop system management) can reduce the GHG emissions involved in producing hybrid maize seeds. This study provides quantitative evidence and a potential strategy for GHG emissions reduction of hybrid maize seed production.
虽然杂交玉米种子生产是全球最重要的农业系统之一，但它的温室气体（GHG）排放及其潜在的缓解措施尚未得到研究。在本研究中，我们使用生命周期评估（LCA）来量化中国西北地区一个以杂交玉米种子生产而闻名的地区 6 家公司的 150 位农民的 GHG 排放。结果表明，杂交玉米种子生产的平均活性氮（Nr）损失和 GHG 排放量分别为 53kgNha 和 8077kgCOeqha。此外，该过程的平均氮和碳足迹分别为 12.2kgNMg 和 1495kgCOeqMg。氮肥和灌溉用电是导致 GHG 排放高的主要原因，分别占总量的 60%和 30%。不同公司的种子生产 GHG 排放因资源投入的不同而有很大差异。150 位农民之间的环境负担也存在很大差异。基于对产量组的分析，我们发现第一组（产量最高的一组）的碳足迹比总体平均水平低 27%。情景分析表明，综合降低氮投入率、优化灌溉和提高产量最终可以将杂交玉米种子生产的碳足迹减少 37%。综合系统方法（例如，ISSM：综合土壤-作物系统管理）可以减少生产杂交玉米种子所涉及的温室气体排放。本研究为杂交玉米种子生产的 GHG 减排提供了定量证据和潜在策略。
