Nitrogen And Phosphorus Input Effects On Three Riparian Forest Soil Nitrogen Burden Quantity In The Upstream Of Wenyu River

This study takes three types of riparian forests in the upstream of WenYu river as study object, setting four levels of nitrogen and phosphorus respectively, by loading quantitative nitrogen and phosphorus interactively、sampling in field, analysis and determination in the lab, researching the max Nitrogen burden quantity in different three typical riparian forest soil, pointed out relationship between loading force of nitrogen and phosphorus with Nitrogen burden quantity, meanwhile by study the correlation between Nitrogen burden quantity with pH、soil organic matter、bulk density, I researched the burden quantity of nitrogen in order to reveal the meaning that the retention of nitrogen and phosphorus for filter mechanism to riparian zone. Main conclusions obtained were as follows:(1) Soil ammonium nitrogen, nitrate nitrogen and total nitrogen content of these three typical riparian forests are characterized by similar vertical pattern, the upper> middle-level> the lower. Although three kinds of riparian forests’ soil nitrogen content varied with the change of seasons, but this kind of vertical gradient relationship remain unchanged. Between each layer and the differences between different nitrogen and phosphorus gradient gradually decreases along with the change of seasons. As ammonium nitrogen by exogenous inputs, the nitrate nitrogen content of vertical and horizontal gradient maximum in June, but later the change trend keeps consistent.(2)Phosphorus input have effected on nitrogen content because of the different existence of nitrogen in the form, three types of riparian forests ammonium nitrogen content of nitrogen input high is affected by Phosphorus, nitrogen input low then the impact is not big. Nitrate performance that phosphorus inputs have an effect on nitrogen content, and with the increase of input content also increases. Total nitrogen content of nitrogen and phosphorus removal effect with each other, but this influence is irregular.(3) Riparian forest soil is one of exogenous nitrogen input as a basic property of bearing capacity and different types of riparian forest soil nitrogen bearing capacity difference is obvious, which conclude Poplar forest, larch forest and spruce forest soil nitrogen bearing capacity value:0.97g/kg,1.05g/kg and1.67g/kg. Soil organic matter content, water content, soil bulk density, and the nitrogen content of the soil are the main factors influencing the bearing capacity of soil nitrogen.