Using the formula to convert fertilization

    Both to fertilize for the sping crops or to fertilize for fruit trees,wheat,rape and other winter crops,it must have a reasonable amount of the fertilizer,but there’re variety of fertilizers in the market,all kinds of manual fertilization suggest that the quantity of fertilizer should instead of nutrient and how can we convert it into the specific fertilizers for farmers?

    Only remember a conversion equation:the quantity of using fertilizer equals the quantity of using nutrient devide nutrient content of fertilizer,which has been marked on the fertilizer bag.Assumption that a plot recommen that the quantity of fertilizer is 8.5kg of purity nitrogen per mu,4.8kg of P2O5,6.5kg of K2O.If only to fertilizer urea(nitrogen content is generally 46 percent),the quantity is 8.5 devided by 46 percent quivalent to 18.5kg.Fertilizer K2SO4(K2O content is generally 50 percent),the quantity is 6.5 devided by 50 percent equivalent to 13kg.

    If using the compound fertilizer,the calculated quantity should judge by the one of least quantity recommended by the applying list. Then add another two kind. If the designate of N,P,K on the compound fertilizer bags is 15:15:15, the quantity should be: 4.8÷15%=32(kilogram). In that case,the phosphrus in the soil can meet the butrient which the crops needed. Since the proportion of the compound fertilizer is fixed, it can not meet the different nutrient need for different crops and soil. Then it needs to add unit fertilizer. The calculate formula is : (Adding Quantity=Recommend Quantity-Applied Quantity)÷Significant Content of the fertilizer that will apply. In this field, 32 kilogram of compound fertilizer has been applied. The content of nitrogen, phosphrus and potassium is 15%,15%,15%. The nitrogen applied is 32×15%=4.8(kilogram),P2O5 and K2O is 4.8 kilogram each. According to the list, the nitrogen should be 8.5 kilogram and the K2O should be 6.5 kilogram. It needs to add Urea(8.5－4.8)÷46%=8(kilogram),SOP(6.4－4.8) ÷50%=3.4(kilogram).