The food-energy-water-carbon nexus in a maize-maize-mustard cropping sequence of the Indian Himalayas: An impact of tillage-cum-live mulching

Amid the current environmental crises that exert enormous pressure on the arable lands, there is a need to adopt environment-friendly effective but highly productive conservation agriculture practices to feed the growing world population. Thus, a study was conducted to test the hypothesis that the inclusion of cowpea (Vigna unguiculata L. Walp) live mulch under no-till and reduced tillage in the summer maize (Zea mays L.) - rainy season maize-mustard (Brassica juncea (L.) czern) sequence would enhance agronomic productivity, energy use efficiency, and water productivity while reducing greenhouse gases emissions. Five tillage treatments viz., no-till, no-till-live mulch, reduce tillage, reduce tillage-live mulch, and conventional tillage were evaluated in three times replicated randomized complete block design. Land productivity for maize-maize-mustard system was the highest under reduced tillage-live mulch. No-till-live mulch had 36.4% lesser energy requirement, 2.4 times more energy productivity than that under conventional tillage. Reduced tillage-live mulch and no-till-live mulch had higher water productivity compared to all other treatments. The conventional tillage had the highest net CO2-eq emission while no-till-live mulch had the lowest. Inclusion of cowpea as live mulch enhanced C sequestration which has the potential to offset approximately half of the total CO2 emission, enhance energy use efficiency, land and water productivity. The findings of this study might be useful to develop a policy for sustainable high productivity through efficient resource use in the Eastern Himalayan Ecosystems that have the potential to become the corn belts of India.