Agricultural Non-Point Source Pollution Characteristics In Hetao Irrigation District

Agricultural non-point source pollution caused by agricultural activities occupy a large proportion in non-point source pollution, which has become the main form of water pollution in the worldwide, in recent years. In China, the use of fertilizers and pesticides become more extensively for high-yield agricultural production, which has caused most of river systems and inland lakes eutrophication by agricultural non-point source pollution. The mainly reason of eutrophication was the laeching of nitrogen and phosphorus from agricultural production activities.Hetao Irrigation District is located in the north shore of the Yellow River, where is an important grain and oil origin. However, the extensively use of chemical fertilizers, pesticides made it face a serious problem of agricultural non-point source pollution. Wuliangsuhai is an inland lake which located in downstream of Hetao irrigation district and accepted more than 90 percent of subsiding water of farmland from Hetao irrigation district, so the lake of Wuliangsuhai eutrophicate severely. In this paper, analysised this six indicators, soil total carbon (TC), total nitrogen (TN), total phosphorus (TP) content in Hetao Irrigation District and water total carbon (TC), total nitrogen (TN), total phosphorus (TP) content in Hetao Irrigation canals and Wuliangsuhai, to explore the impact of agricultural activities for Hetao Irrigation District and Wuliangsuhai water environment particularly. This study could provide a theoretical basis to address non-point source pollution problem and rational fertilization of Hetao Irrigation and control eutrophication in Wuliangsuhai.The main conclusions are as follows:1.Through the soil (0-30cm) total carbon, total nitrogen, total phosphorus content distribution and ecological stoichiometry characteristics analysis, found soil carbon and nitrogen content and land use in Hetao Irrigation District were significantly related (P<0.01), the total carbon content in Hetao Irrigation District is significantly lower than other non-farming areas, total nitrogen and phosphorus content was significantly affected by the amount of fertilizer and significantly associated with land use(P<0.01).Through the analysis of ecological stoichiometry found that soil contain high levels of nitrogen and phosphorus, and have high leaching risky.2.In August 2012, October 2012 and May 2013 acquisition Hetao Irrigation District canal water samples, through analysis found that in October 2012 autumn irrigation period, water total nitrogen, total phosphorus content of the Hetao Irrigation District canal was significantly increased, and total nitrogen, total phosphorus were significantly correlated(P<0.01).Description autumn irrigation significantly affect the nitrogen and phosphorus content of Hetao Irrigation.3.In August 2012, October 2012 and May 2013 collected Wuliangsuhai water samples, through analysis found that total nitrogen, total phosphorus content spatial distribution changed identically and correlation was significant, Indicate that subsiding water of farmland significantly influence content of nitrogen and phosphorus in Wuliangsuhai.4.Hetao Irrigation water pollute severely, most parts has not reached the V water lever which allow the use of agricultural activities. The water inside Wuliangsuhai was not suitable for fish farming.