Soil Organic Carbon and System Environmental Footprint in Sugarcane-Based Cropping Systems Are Improved by Precision Land Leveling

A six-year experiment (2009 to 2015) was conducted on sugarcane-based cropping systems in farmers' fields to examine the effects of precision land leveling (PLL) compared to traditional land leveling (TLL) in terms of soil organic carbon (SOC), greenhouse gas emissions, irrigation water requirements, and system productivity and profitability. Twelve treatments compared different sugarcane sowing regimes and crops in rotation under both PLL and TLL. Spring-sown sugarcane grown in rotation with rice, potato, and wheat under PLL had the highest production (89.7 kg ha(-1) day(-1)) and required 142 cm irrigation water, which was 35.1% less water than a commonly practiced cropping system with late-sown sugarcane grown in rotation with rice and wheat only under TLL). Cropping systems established under PLL had higher land use efficiency (ranging between 64.9 and 86.2%), higher energy productivity (90.7 to 198.6 GJ ha(-1)), and lower greenhouse gas emissions (5249.33 to 944.19 kg CO2 eq ha(-1) year(-1)) than those under TLL. As well, treatments under PLL had increased levels of SOC, particularly in the upper soil layers, relative to SOC in treatments under TLL. Combining PLL with diversification of crops in sugarcane cropping systems has the potential to sustainably increase farmers' land productivity and profitability while improving soil health and reducing irrigation requirements. These benefits are likely to have applications in other sugarcane-based cropping systems in similar agro-ecologies.