Properties of Soil Nutrient-supply in the Balanced Fertilization Practices

A formula was established by the outputs of nutrient-deficient plots instead of the CK plots,which is near to the natural conditions and lead to the increase of soil nutrient-supplying potential but the decreaes of fertilization.The output and the amount of nutrient uptake at the nutrient deficient plots are the basic parameters for forecasting the soil nutrient-supplying capacity and correcting the coefficients of available nutrients.The three methods discussed in the paper had higher precision in the forecast of soil nutrient-supply.The fitting value was over 90%.