Deficit Irrigation With Wastewater in Direct Sowed Silage Maize Reduces Co2 Emissions From Soil by Providing Carbon Savings

Abstract

Direct sowing and deficit irrigation practices can reduce the effect of wastewater on CO2 emissions from soil by providing carbon savings. Therefore, the effect of domestic recycled wastewater uses at different levels in irrigation under conventional tillage and direct sowing practices on the CO2 emission from soil at the end of the vegetation period of silage maize was investigated by comparing it with full irrigation of fresh water. Both organic carbon and CO2 emissions in the second year in fully irrigated treatments were higher than those in the first year. The CO2 emission in the full irrigation with wastewater (0.263 g m(-2) h(-1)), compared to full irrigation with fresh water and 33 and 67% deficit irrigations with wastewater, was higher at 23.4, 25.0, and 59.3%, respectively. Direct sowing practice also (0.193 g m(-2) h(-1)) resulted in 17.0% less CO2 emission as compared to conventional tillage. The positive linear relationships of H2O emission and the soil moisture content at different depths (5, 10, and 20 cm) with CO2 emission were significant, and the negative relationships with the soil temperatures were also found. It has been concluded that deficit irrigation and direct sowing applications can be practical for reducing CO2 emissions from soil in wastewater irrigation conditions.