Study On Paddy Applying Organic Manure Effect On Dissolved Organic Matter And Nitrate Nitrogen Leaching Losses In Ningxia Yellow River Irrigation Area

In the agricultural production process,Ningxia Yellow River irrigation manureemployment quantity is high, causing the farmland to draw back in the water the nitratenitrogen content too high issue, intensified the water pollution eutrophication of Yellow River,how therefore explores leaching out of the utilization technology control nitrate nitrogen insoil regarding the water quality of Yellow River to have the important safeguard significancesafely.This research through region investigation and study and plot experimental study ricepaddy soluble organic matter (DOM) content and between farmland nitric nitrogen leachingout relations.This preliminary operation resin core law adsorption determination paddy ricewinter spring the fallow time as well as paddy rice growth season intrinsic soil30cm,60cm,the90cm soil layer place nitric nitrogen leaching out quantity, and obtains the leaching outquantity change rule.And determination correspondence soil layer DOM and SOM content;Carries on the investigation and study to the Ningxia Yellow River irrigation peripherallocality, obtains Ningxia Yellow River irrigation DOM content level and so on, studies DOM,SOM and the nitric nitrogen leaching out quantity relations, obtains following conclusion:(1)Ningxia Yellow River Irrigation on the basis of the conventional fertilizationincreased application of organic fertilizer, can effectively reduce the total amount of soil in60cm and90cm soil annual nitrate leaching. and with the increase of fertilizer,nitrate-nitrogen leaching was gradually reduced.(2)Application the organic fertilizer after the rice paddy, the30cm soil layer in the paddyrice growth season locates the nitrate nitrogen leaching out quantity of D1processing toincrease, the nitrate nitrogen leaching out quantity of D2processing reduces. Two processingreduce in60cm and90cm soil layer place leaching out quantity, the reduced proportion of D2processing is higher than D1processing.(3)After applying organic fertilizer in paddy field to move the nitrate-nitrogen leachingprocess, decreased level of leaching, released from the excess of n during critical growingperiod of rice and promote growth. Slow seedling to rice at tillering stage is the most acutephase of the nitrate-nitrogen leaching, control of nitrate-nitrogen leaching in this period iscrucial, at the booting stage, and harvest during grain filling period, relatively few amount of nitrate-nitrogen leaching. Therefore to strengthen during the sustained period of seedling andtiller both control of nitrate-nitrogen leaching.(4)In the rice growing season, after applying organic fertilizer in rice field, rice paddiesin the DOM content is improved. DOM and SOM content in soils with increasing soil depthand constantly decreasing, SOM content of SOM content higher than the initial growth ofrice at harvest time, DOM content lower than the initial growth of rice at harvest time theDOM content. In60~90cm and soil0~30cm soil, DOM level3processing showed adeclining trend. Soil30~60cm soil,3reduced the trend of increasing basic rendering.(5)On the DOM and soil correlation analysis between nitrate-nitrogen leaching, in0-30cm and0-90cm, nitrate-nitrogen leaching between the DOM rendering negative,indicating that as the DOM content in soil increases, declining levels of nitrate-nitrogenleaching.(6)Relative to the pilot community, most of the farmland in Ningxia irrigation area of theDOM content is low. Combines research findings, as well as the annual agriculturalproduction in Ningxia irrigation area, in the promotion of application of organic fertilizer inirrigated area of Ningxia, which not only reduce the amount of nitrate leaching and increasingrice production and raise farmers ’ income.