Seasonal Variation Of N、P、K In The Soil Of The Typical Farmland In The Headwater Region Of The Liao He River And The Adsorption Characteristics

This paper discusses the seasonal variation of N、P、K in the soil of the typicalfarmland in the headwater region of the Liao He Rivernd and the adsorptioncharacteristics. The purpose is to provide theoretical basis for the prediction of thenon-point source pollution and protection of the environment in Headwater Region ofLiao He River.The experimental field this paper is the following five types:normalplanting test field, soil testing formula test field, longitudinal ridge test field, blankcontrol1and2test field.Conclusions are as follows:(1)T he content of total nitrogen,available phosphorus, available potassium is higher in autumm than that in spring;thecontent of hydrolytic nitrogen, ammonium nitrogen, nitrate nitrogen, total potassiumis lower in autumn than that in spring;the rate of water content is higher in autumnthan that in spring,soil pH is slightly lower in autumn than that in spring;the TOCcontent in surface soil is slightly lower in autumn than that in spring,but it is notchange in bottom soil;the cation exchange capacity is higher in autumn than that inspring.(2)The content of total nitrogen, hydrolyzable nitrogen, ammonium nitrogen,nitrate nitrogen, available phosphorus, total phosphorus, available potassium is higherin the surface soil than that in the bottom soil;The changes of the content of totalpotassium is not obvious;the changes of the content of the rate of water content is notobvious;the pH in the bottom soil was closer to neutral compared with the surfacesoil;the TOC content in the surface soil is much higher than that in the bottom soil;the cation exchange capacity is higher in the surface soil than that in the bottomsoil.(3)Ammonium nitrogen’s adsorption kinetics thermodynamics compared with thepseudo-first-order kinetic model.The adsorption process of adsorption follows thelinear adsorption.Its adsorption capacity will be increaseed at low temperature.In this kind of soil,When the phosphorus concentration is low，the adsorption capacity ofammonium nitrogen is stronger with pH increased,and it is opposed when theconcentration is high.(4)The adsorption of phosphorus’s adsorption kinetics comparedwith the pseudo-first-order kinetic model.The adsorption process of adsorptionthermodynamics follows the Langmuir adsorption.Its adsorption capacity will bereduced at low temperature.In this kind of soil, the adsorption capacity of phosphorusslightly worse in particle size of0-0.25mm soil.he adsorption capacity of phosphoru isstronger with pH increased.(5)Nitrate nitrogen is not absorbed in the soil.