Singh Raman Jeet, Meena Roshan Lal, Sharma N K, Kumar Suresh, Kumar Kuldeep, Kumar Dileep
ICAR-Indian Institute of Soil and Water Conservation, 218 Kaulagarh Road, Dehradun, 248 195, India.
ICAR-National Bureau of Soil Survey and Land Use Planning, Research Centre, Udaipur, Rajasthan, 313 001, India.
Environ Monit Assess. 2016 Feb;188(2):79. doi: 10.1007/s10661-015-5085-2. Epub 2016 Jan 6.
Reducing the carbon footprint and increasing energy use efficiency of crop rotations are the two most important sustainability issues of the modern agriculture. Present study was undertaken to assess economics, energy, and environmental parameters of common diversified crop rotations (maize-tomato, and maize-toria-wheat) vis-a-vis traditional crop rotations like maize-wheat, maize + ginger and rice-wheat of the north-western Himalayan region of India. Results revealed that maize-tomato and maize + ginger crop rotations being on par with each other produced significantly higher system productivity in terms of maize equivalent yield (30.2-36.2 t/ha) than other crop rotations (5.04-7.68 t/ha). But interestingly in terms of energy efficiencies, traditional maize-wheat system (energy efficiency 7.9, human energy profitability of 177.8 and energy profitability of 6.9 MJ/ha) was significantly superior over other systems. Maize + ginger rotation showed greater competitive advantage over other rotations because of less consumption of non-renewable energy resources. Similarly, maize-tomato rotation had ability of the production process to exploit natural resources due to 14-38% less use of commercial or purchased energy sources over other crop rotations. Vegetable-based crop rotations (maize + ginger and maize-tomato) maintained significantly the least carbon footprint (0.008 and 0.019 kg CO2 eq./kg grain, respectively) and the highest profitability (154,322 and 274,161 Rs./ha net return, respectively) over other crop rotations. As the greatest inputs of energy and carbon across the five crop rotations were nitrogen fertilizer (15-29% and 17-28%, respectively), diesel (14-24% and 8-19%, respectively) and irrigation (10-27% and 11-44%, respectively), therefore, alternative sources like organic farming, conservation agriculture practices, soil and water conservation measures, rain water harvesting etc. should be encouraged to reduce dependency of direct energy and external carbon inputs particularly in sub-Himalayas of India.
减少作物轮作的碳足迹并提高其能源利用效率是现代农业最重要的两个可持续发展问题。本研究旨在评估印度喜马拉雅地区西北部常见的多样化作物轮作（玉米-番茄和玉米-油菜-小麦）相对于传统作物轮作（如玉米-小麦、玉米+生姜和水稻-小麦）的经济、能源和环境参数。结果表明，玉米-番茄和玉米+生姜轮作彼此相当，以玉米当量产量计算（30.2-36.2吨/公顷），其系统生产力显著高于其他作物轮作（5.04-7.68吨/公顷）。但有趣的是，在能源效率方面，传统的玉米-小麦系统（能源效率为7.9，人力能源利润率为177.8，能源利润率为6.9兆焦/公顷）明显优于其他系统。玉米+生姜轮作因不可再生能源消耗较少，比其他轮作表现出更大的竞争优势。同样，玉米-番茄轮作的生产过程有能力利用自然资源，因为其商业或购买能源的使用量比其他作物轮作少14%-38%。与其他作物轮作相比，以蔬菜为主的作物轮作（玉米+生姜和玉米-番茄）的碳足迹显著最低（分别为0.008和0.019千克二氧化碳当量/千克谷物），盈利能力最高（分别为154322和274161卢比/公顷净回报）。由于五种作物轮作中能源和碳的最大投入分别是氮肥（分别为15%-29%和17%-28%）、柴油（分别为14%-24%和8%-19%）和灌溉（分别为10%-27%和11%-44%），因此，应鼓励采用有机农业、保护性农业措施、水土保持措施、雨水收集等替代来源，以减少对直接能源和外部碳投入的依赖，特别是在印度的喜马拉雅山麓地区。
