Integrating Ecological Restoration of Agricultural Non-Point Source Pollution in Poyang Lake Basin in China

This study addresses the excessive consumption of river basin water from the Poyang Lake area in China. Consumption of water for irrigation, together with the discharge of agricultural non-point source pollution, is seriously affecting the water quality of Poyang Lake. This study assesses the application of integrated ecological restoration technology for agricultural non-point source pollution in the Ganfu Plain Area, which is an important agricultural production base in the Poyang Lake basin. The results indicated that the water-fertilizer comprehensive regulation mode for double-cropping rice provided water savings of 10.4% and increased rice yield by 6.5% per hectare. Furthermore, it reduced drainage water pollution by 20.4%, and emissions of ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3−-N), total phosphorus (TP), and total nitrogen (TN) from rice paddy surfaces by 18.6%, 11.1%, 15.4%, and 16.0%, respectively. The eco-channel–pond wetland system effectively reduced TN and TP pollutant levels in rice paddy drainage water; the eco-channel reduced TN and TP by 9.3% and 14.0%, respectively; and the pond wetland system showed reductions of 8.6% and 22.9%, respectively. The “three lines of defense” purification technology, including rice field source control, eco-channel interception, and pond wetland purification, removed 29.9% of TN and 44.3% of TP.