Appraised To The Soil Nutrient Current-situation And Established The Index System Of The Soil Testing Fertilization In Xiangtan

Through massive sampling and investigation combining with "3414"field experiment and the need fertile law of rice,the soil fertility condition of xiangtan were analysised and appraised, the fertile(include nitrogen, phosphorus, potassium) effect and mode of rice were studied,the best optimum quantity and proportion of these fertilizers was proposed, then a technician plan of large scale fertilizers application is devised and promoted in Xiangtan county.The main results as follow:1、 The soil of Xiangtan county was acidity (the probablity of soil pH on strong acidity and slight acidity soil was respectively35.97%and30.57%),the organic matter was rich(the probablity of organic matter of rich was53.31%),the whole nitrogenous was rich(the probablity of whole nitrogenous of ich and very rich was respectively43.88%and13.67%),the alkali-hydrolyzable nitrogenous was proper (the probablity of alkali-hydrolyzable nitrogenous of proper was respectively50.00%), the whole phosphate was proper or rich(the probablity of whole phosphate of proper and rich was respectively28.42%and32.37%), the quick-acting phosphate was lack(the probablity of quick-acting phosphate of proper and rich was respectively20.13%and35.43%), the whole potash was rich(the probablity of whole potash of very lack,lack and proper was respectively16.91%,39.57%and29.14%), the quick-acting potash was rich(the probablity of quick-acting potash of proper,rich and very rich was respectively25.83%,38.41%and11.59%).2、 The models between nitrogen and early rice was Y=0.19Ln(X)+409.4, and that of late rice was Y=0.60Ln(X)+275.8; the model between phosphate and early rice was Y=-1.44Ln(X)+2.9, that of late rice was Y=14.69Ln(X)+53.1, the models between potassium and early rice was Y=-1.27Ln(X)+10.2, that of late rice was Y=-2.42Ln(X)+15.8. Averagely, the quantities of N,P,K components were2.25kg,1.02kg,2.39kg for early rice and were2.33kg,0.98kg,2.63kg for late rice per100kg yields at higher,middle lower fertility.3、 The optimum quantities and proportions of the NPK components in different fertilizer level according to different village in the Xiangtan and the yield level. The soil test fertilization technology is implemented to make a fertilizer plan for early and late rice and the technology is promoted in Xiangtan which has been promoted in32,400hectares..The average yield is8800kg/hm2(rice produetion inereases rate is7.1%)and effers1026yuan per hectare additional output illustrated the technology brings good economic result.