A study on the farmland nutrient balance and the variation dynamic of soil nutrients in Zizhong county,Sichuan province

According to the statistical;material and analytic data of soil,the farmland nutrient balance and the dynamic changing tendency of soil nutrients from 1985 to 1999 in Zizhong county were discussed. The result showed that in 1990s, the nitrogen in farmland was surplus over 50 percent at present time; the content of phosphorus was varying throughout from deficiency to surplus,now the content was surplus over 80 percent; the potassium was deficient all along with high proportion,however,upto 1999,soil K content was tending towatds balance. Meanwhile, the dynamic changing tendency during recent 20 years was analyzed by comparing the content of soil nutrient between 1983 and 2000, the effect of farmland nutrient balance on soil nutrients level was discussed too. The regulating ways was given according to the study results.