| Because of the blind pursuit of agricultural production,the agricultural chemicals s uch as pesticides,chemical fertilizers and plastic sheeting was excessive used,in additio n,pesticide,fertilizer utilization rate is very low.The above phenomena cause a large am ount of N,P and other nutrients to be washed to rivers,lakes and other bodies of water with agricultural water withdrawal and rainwater.And then groundwater pollution and s urface water eutrophication take place.This paper mainly studies the effect of agricultur al fertilizer non-point pollution on the quality of surface water and groundwater and the effect of different fertilization techniques on the pollution reduction of fertilizer no-poin t pollution.The following main research results are obtained.1.According to the investigation on the influence of non-point source pollution of chemical fertilizer on water body of Dagu river,we came to the conclusion that(1)the concentration of nitrates,ammonia nitrogen and total nitrogen in each section of the Dagu River Basin was lower than before rain which showed that heavy rainfall and surface runoff had a certain dilution effect on river water.However,the permanganate index didn't change significantly,and the total phosphorus was not detected in all sections;The nitrate,ammonia nitrogen,total nitrogen and potassium permanganate were all higher than the dry period in wet season of the Dagu river basin.(2)The total content of nitrogen and nitrate in the groundwater near the field and greenhouse were generally higher,and some of the sampling points were far beyond the class V water quality indicators specified in the Groundwater Quality Standard(GB/T 14848-93).2.By doing research work on the promotion of water fertilizer integration technology in Qingdao five agricultural district(city)of Huangdao District,Jimo City,Jiaozhou City,Pingdu City and Laixi city,the result shows that the proportion of planting area using water and fertilizer integrated technology was very low in five agricultural areas of Qingdao city.The proportion was less than 10% of the except the facilities vegetables were about12.3%.Because of its technical characteristics,Water and fertilizer integration technology could significantly reduce the use of chemical fertilizers on the premise of satisfying crop demand.It can not only improve the economic benefits,but also reduce the amount of fertilizer residues in the soil,thereby reducing non-point source pollution.3.Field test of organic matter upgrading technology shows that using maize straw-decomposing inoculant in the stage of straw application significantly increased Soil organic matter and the content of alkali hydrolyzable nitrogen,available phosphorus and available potassium,and then plant grew vigorously,the stem length,stem diameter and disease resistance increased significantly.At the same time,the application of this technology improved the soil structure,raised soil retention performance,thereby nitrogen and phosphorus pollutants that flow into groundwater and surface water by leaching and runoff was significantly reduced.4.The research of testing soil for formulated fertil-ization shows that(1)the potato yield in the following decreasing order for the in-situ experiment of fertili zer utilization : formula fertilization> conventional fertilization> no fertilization,and t he fertilizer utilization rate of the formula fertilization treatment was higher than that of the conventional fertilization treatment.The utilization rate of nitrogen fertilizer was ge nerally higher than that of potash and phosphate fertilizer rate.(2)In the control of the total amount of nitrogen fertilize expriment,optimized nitrogen treatment yield of potato was the highest as well as obviously improved the quality of potatoes.Compared with the 70% and 130% optimized nitrogen treatments,the nitrate,protein,starch,potassium,vitamin A and vitamin C of potato under the optimized nitrogen treatment were the highest.(3)Testing soil for formulated fertil-ization had obvious influence on the emission reduction of nitrogen and phosphorus,with this technology the nitrate nitrogen,alkali-hydrolyzable nitrogen,total nitrogen,effective phosphorus and total phosphorus content were higher than conventional fertilization of the three soil layers measured in the potato growth medium as well as after harvest.Combined with fertilizer utilization rate test,it can be concluded that Testing soil for formulated fertil-ization technology improved the absorption of nitrogen and phosphorus by potato,thus effectively reducing the residual of nitrogen and phosphorus in the soil. |
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