Tillage and irrigation methods effects on energy use and greenhouse gas emissions in grain corn production

Abstract

In this study, the effect of tillage and irrigation methods on energy use, energy indices, and greenhouse gas (GHG) emissions of grain corn production was evaluated. The research was conducted in the form of a split plot experimental design with three replicates in Fars province, Iran. Main plots were irrigation methods including surface irrigation (gated pipe), drip irrigation, and sprinkler irrigation. Tillage methods including no-till (NT), reduced tillage (RT), and conventional tillage (CT) were considered as sub plots in this research. Results showed that irrigation method had significant effect on energy use, output energy, energy indices, and GHG emissions of grain corn production, while tillage method had significant influence only on energy use, output energy, and net energy gain. Surface irrigation had the highest input energy (165856 MJ ha^-1) and GHG emission (29376 kg CO₂e ha^-1) followed by sprinkler (117662 MJ ha^-1 and 20363 kg CO₂e ha^-1) and drip irrigations (88597 MJ ha^-1 and 15025 kg CO₂e ha^-1). Drip and sprinkler irrigations reduced input energy for 45 and 29% and the total GHG emissions for 48.9 and 30.7%, respectively compared to the surface irrigation in grain corn production. No-till reduced energy input and increased energy output by 2.3 and 9.8%, respectively compared to the conventional tillage. Results of this study also showed that corn production cropping system involving an efficient irrigation method (such as drip irrigation) and conservation tillage would be an energy efficient cropping system with low environmental pollution risks.