稻田在不同水分管理方式下COD动态排放规律研究

Study on dynamic emission law of COD in paddy field under different water management modes

农业面源污染问题是全球水质恶化的主要原因,而COD是指标水体有机污染的一项重要指标。水稻作为耗水量最大的农作物,由于不科学的灌溉方式给环境带来了严重的面源污染。为了探究适宜贵州省的水稻种植技术,经过多年试验提出了科学蓄雨型节水灌溉。本文通过科学蓄雨灌溉与传统淹灌、控制灌溉进行对比试验,对稻田整个生育期内COD田面径流和地下淋溶排放浓度和排放量进行动态研究,结果表明:在整个生育期的大部分时段内,科学蓄雨灌溉渗漏水中COD浓度显著低于淹灌和控制灌溉,但科学蓄雨灌溉田面径流COD浓度较高。水分管理方式对COD排放总量影响显著,科学蓄雨灌溉和控制灌溉的COD排放总量显著低于传统淹灌。相对于传统淹灌,科学蓄雨灌溉降低COD排放量达38.4%。

Agricultural non-point source pollution is the main cause of global water quality deterioration,and COD is an important indicator of organic pollution.As the crop with the largest water consumption,rice has brought serious nonpoint source pollution to the environment due to unscientific irrigation methods.In order to explore the rice planting technology suitable for Guizhou Province,scientific rain storage water-saving irrigation was put forward after years of experiments.Through the comparative experiment between scientific rain storage irrigation and traditional flooding irrigation and controlled irrigation,this paper makes a dynamic study on the COD field runoff and underground leaching emission concentration and emission in the whole growth period of paddy field.The results show that the COD concentration in the leakage water of scientific rain storage irrigation is significantly lower than that of flooding irrigation and controlled irrigation,but the COD concentration in the field runoff of scientific rain storage irrigation is higher.Water management has a significant impact on the total COD emission.The total COD emission of scientific rain storage irrigation and controlled irrigation is significantly lower than that of traditional flooding irrigation.Compared with traditional flooding irrigation,scientific rain storage irrigation reduces COD emission by 38.4%.