Tillage and crop residue effects on the energy consumption, input–output costs and greenhouse gas emissions of maize crops

Improving energy use efficiency (EUE) is critical for increasing farmers’ incomes, developing sustainable agriculture, and mitigating greenhouse gas (GHG) emissions. However, data on EUE, net income, and GHG emissions across various tillage and crop residue (straw) treatments remains scarce. This study aimed to estimate these variables across different tillage and straw treatments used in summer maize production in a winter wheat-summer maize cropping system in China’s Loess Plateau. Tillage treatments included chisel plowing, no tillage, and moldboard plowing. These were studied both with straw returned to the soil, or removed. All activities and production processes were recorded. The results demonstrate that fertilizer especially nitrogen fertilizer, and to a lesser extent, the fuel used for tillage, sowing and harvesting, were the two major consumers of energy and producers of GHG emissions. These results indicated that the use of chisel plow or conducting no tillage with straw returned to the soil, can reduce energy consumption and GHG emissions, and improve the economic benefits of summer maize production in the region, compared with conventional moldboard plow tillage without straw (which is typically burned off). The results show that further improvements could be facilitated by improving the utilization of nitrogen fertilizer, returning straw to the soil, and reducing tillage. These practices can reduce GHG reductions, and improve EUE and farmers’ incomes.