Effects of Different Fertilizer Amount on the Dynamics of Soil Potassium

The available K in soil is decreasing,which is harmful for the sustainable use of soil potassium.Therefore,the change of the soil potassium under different potassium fertilizer amount was studied in this article,which provides basis for the sustainable use of the soil potassium and reasonable fertilizer using.The result indicated that the soil potassium wasdecreased year by year when there was only of nitrogen and phosphorus fertilizer application or non-fertilizer treats.The average annual decrease rate was 2mg/kg every year.The soil potassium maintained the former level when the potash fertilizer amount was 112.5kg/ha.The available potassium increased when the fertilizer amount was 225kg/ha.The proportion of available potassium in the total potassium could also be increased.