Changes in GHG Emissions Based on Irrigation Water Quality in Short-Term Incubated Agricultural Soil of the North China Plain

Abstract

A worsening water shortage is threatening the sustainable development of agriculture in the North China Plain (NCP). How to make effective use of inferior water resources and alleviate the impact of insufficient water resources on agricultural environments is one of the urgent problems in agricultural production. Although agriculture plays an important role in greenhouse gas (GHG) emissions, the effects of irrigation water quality on such emissions in the NCP are not clear. In this study, we used a short-term incubation experiment to test the effects of the irrigation water quality (underground water (UW), saline water (SW), and reclaimed water (RW)) and frequency (high (H) and low (L)) on regulating the soil GHG emissions of the NCP. The results indicated that RW treatment increased the CO2 and N2O emissions by 15.00% and 20.81%, respectively, and reduced the CH4 uptake by 12.50% compared with the UW treatment. In addition, SW treatment decreased the CO2 and N2O emissions and CH4 uptake by 35.18%, 40.27%, and 20.09% against UW treatment, respectively. The high-frequency water added to the soil significantly increased the GHG emissions for all water qualities applied. Compared with UW, the global warming potential was significantly increased by RW_H and RW_L with 26.48% and 14.5% and decreased by SW_H and SW_L with 32.13% and 43.9%, respectively. Compared with the increase brought by reclaimed water, changing irrigation water sources from conventional groundwater to saline water (4 g L−1) will moderately reduce GHG emissions under the worsening water shortage conditions occurring in the NCP.