Studies On Abundance And Deficiency Index Of Nitrogen, Phosphorus And Potassium For The Soil Based On The Experiment Of "3414"

This paper was based on the experiment of"3414". According to the data of 21 county seats'soil testing and fertilizer recommendation, study on abundance and deficiency index of nitrogen, phosphorus and potassium for the soil. The results are show as follows.The plentiful-lack indexes are difference by three kinds of relative yields (the first relative yield is the ratio of CK plot and N2P2K2 plot, the second relative yield is the ratio of CK plot and the plot with maximum yield in 4 levels, the third relative yield is the ratio of CK plot and the plot with maximum yield in14 treats). Many points must be exclusive, when using the second relative yield. Using the third relative yield, the numeric of R2 is higher, when fitting logarithmic function. When integrating the plentiful-lack index of nitrogen, phosphorus and potassium for the soil, we used mean value method and anew partition method. Because determine the range of maximum-minimum is not feasible. In this study, we used anew partition method to establish the soil nutrient plentiful-lack Index of Inner Mongolia. The soil nutrient plentiful-lack Index of Inner Mongolia is that: Total nitrogen of soil is extremely low, when its value is below 0.37 g/kg. Soil total nitrogen is deficient, when its value is from 0.37-0.87 g/kg. When its value is from 0.87-1.71, soil total nitrogen is in the middle degree. When its value is more than 1.71 g/kg, soil total nitrogen is abundant. Soil available phosphorus is extremely low, when its value is below 1.7mg/kg. When its value is from 1.7-8.0 mg/kg, soil available phosphorus is deficient. When its value is from 8.0-31.6 mg/kg, soil available phosphorus is in middle degree. When its value is over 31.6 mg/kg, soil available phosphorus is abundant. Soil available potassium is extremely low, when its value is below 35mg/kg. When its value is from 35-92 mg/kg, soil available potassium is deficient. When its value is from 92-199 mg/kg, soil available potassium is in middle degree. When its value is over 199 mg/kg, soil available potassium is abundant.