Tillage and straw affect soil CO2 emissions in a rain-fed corn field

A field study was conducted to assess the effects of soil tillage practices and straw management on soil CO2, and yield-scaled CO2 emissions in a rain-fed summer corn field on the Loess Plateau. Tillage treatments consisted of sub-soiling tillage (CP), no tillage (NT) and moldboard plow tillage (CT). Wheat straw was removed from half of the CP, NT and CT plots after harvest, allowing us to test for interactive effects between tillage practices and straw management. Soil CO2 emissions, soil moisture and soil temperature were recorded 12 times throughout the growing season. Across treatment combinations, the highest cumulative CO2 emissions were recorded in CT , the lowest emissions were recorded in NT. Straw return increased cumulative CO2 emissions to 19%–27% compared to the straw removal treatment. We concluded that conservation-focused tillage systems, i.e., no tillage, could reduce yield-scaled CO2 emission; thus, they can produce better yields and provide environmentally friendly options.