ICAR National Professor Project, Department of Soil Science, Punjab Agricultural University, Ludhiana 141004, India.
Sci Total Environ. 2018 Dec 10;644:611-623. doi: 10.1016/j.scitotenv.2018.07.018. Epub 2018 Jul 11.
Green Revolution led to an unprecedented increase in world food production but with a significant carbon footprint raising concerns about its sustainability. With the rising global population and the need to produce more food, the farming systems will have to be sustainable. To identify farming practices that increase yield with minimum environmental cost, it is imperative to quantify the environment footprint of different technologies. The present study quantified the impact of Green Revolution technologies on the carbon footprint of intensive crop production systems, mainly rice-wheat in an agriculturally important region of Indo-Gangetic Plains. The results revealed the overriding importance of groundwater irrigation and fertilizer use in determining the carbon footprint of crop production, and underpin the opportunities for their mitigation. Intensification of agriculture resulted in ~2.5 fold increase in food grain production and 3-fold increase in emission of greenhouse gases (GHGs) during 1980 to 2015. Carbon sustainability of food grain production declined with time indicating that energy use efficiency is decreasing; the greatest decline being in rice followed by wheat and negligible in maize. Options for mitigating environment footprint of food grain production included partially replacing area under rice with other less water requiring crops, improving irrigation water productivity and pumping efficiency, and increasing fertilizer use efficiency. Maize with low global warming potential and high C sustainability appeared a viable option for diversification. The implementation of these mitigation measures can reduce environment footprint by 46%. Preventing crop residue burning will not only offset the associated GHG emissions (6266 Gg yr) but can also improve soil health if returned to the soil. Intensification of agriculture has co-benefit of C sequestration in soil, which besides offsetting emissions by ~10% is an important determinant of soil quality and sustainability.
绿色革命带来了世界粮食产量的空前增长，但随之而来的是碳排放问题，这引发了人们对其可持续性的担忧。随着全球人口的增加和对更多粮食生产的需求，农业系统必须具有可持续性。为了确定既能提高产量又能将环境成本降至最低的农业实践，量化不同技术的环境足迹至关重要。本研究量化了绿色革命技术对集约型作物生产系统（主要是印度-恒河平原农业重要地区的稻麦轮作）的碳足迹的影响。研究结果表明，地下水灌溉和化肥使用对作物生产的碳足迹具有决定性影响，这为减轻其影响提供了机会。农业集约化导致 1980 年至 2015 年期间粮食产量增加了 2.5 倍，温室气体（GHG）排放量增加了 3 倍。粮食生产的碳可持续性随时间下降，表明能源利用效率正在降低；其中水稻的下降幅度最大，其次是小麦，玉米则几乎没有下降。减轻粮食生产环境足迹的选择包括部分用其他耗水量较少的作物替代水稻种植面积，提高灌溉水生产力和抽水效率，以及提高化肥利用率。具有较低全球变暖潜势和较高 C 可持续性的玉米似乎是一个可行的多样化选择。实施这些缓解措施可以减少 46%的环境足迹。如果将作物秸秆还田，不仅可以抵消与之相关的温室气体排放（6266Gg yr），还有助于改善土壤健康。农业集约化还有利于土壤中的碳封存，这不仅可以抵消约 10%的排放量，还是土壤质量和可持续性的重要决定因素。
