Study On The Dynamics Of Potassium Releasing And Fixing Of Several Phaeozem In Jilin Province

This research selected 10 cultivated horizon of phaeozem that have a representatives from Jilin province. The aim was to research the dynamics of non-exchangeable releasion ,adsorption of potassium and desorption of potassium,the fixed quantity and released quantity of soil on the condition of k-added, and the experiment of soils exhaust.Using potassium supplying capacity,potassium supplying intensity and potassium supplying velocity evaluated the soils of potassium supplying characterist of the soils.this article provided a scientic basis on promoting the percentage of k used.The traditional equilibrium method was adopted when studied nonexchangeable k releasing. Elovich equation,zero order equation ,first order equation and parabolic equation was used to describe the nonexchangeabe k releasing process.Then the best model was selected to describe nonexchangeable k release and its velocity. The result showed that parabolic equation was the ideal dynamics model, on the conditions of 25 ℃ and alterative freezing and thawing with rate constant and standard deviation ranging from 0.952-0.9876,0.85-10.28 and 0.9272-0.9872,0.69-13.11 respectively. No.1 and No.2 soils had the highest release quantity and velocity among ten soils.No.3 and No.4 soil were higher.The velocity of nonexchangeable K releasing was decreating with the time and it was higher in the treatment of alterative freezing and thawing than 25℃.In a word ,alterative freezing and thawing could accelerate nonexchangeable k releasing in soils.Its release quantity and velocity were higher obviously than the condition of 25 ℃ and its releasing time kept longer.Kinetics of adsorption and desorption characteristics were studies using continuous flowing method. The continuous desorption or adsorpted time,the biggest adsorption and desorption quantity,average adsorption and desorption velocity and biggest adsorption and desorption rates had a great difference among different soils. Two-constant equation can describe the k adsorption and desorption of soils in the experiment better. The soils with higher adsorption quantity need longer time to balance. The lower ones need shorter time at the same time. Comparing two different content of potassium,we can see that the bigger the density was,the higher adsorption quantity was. And the faster rate it had,and the balance time was shorter.In order to study the fixation capacity of soils to added K and the realse of fixed K,this research adopted lasting wet method. The result showed that the K quantity of fixation and K quantity of added...