Determination Of Fertilization Indexes Based On The Objective Yields Of "3414" Experiment And Studies Of Affecting Factors

Based on the provincial"3414"fertilization experiment of 2006, the rules of 5 parameters setting for the objective yield method were studied, and the factors affecting these parameters and the possible correlations were analyzed. The results show that it is more reasonable to rationalize NPK fertilization rates by referring the highest yield of the 14 treatments or the highest yield of the 4 levels of NPK. In respond to the ground yields, the fertilization rates of N, P, K can be determined by aligning the resulted yields of N absent block or controlled block, P absent block, K absent block of the"3414"fertilization experiment as the starting yields. N, P2O5, K2O up taken by unit of agronomic yield can be estimated by results of N2P2K2 treatment or by the mean result of the 14 treatments. By selecting N absent block (N0P2K2), P absent block (N2P0K2), K absent block (N2P2K0) as the nutrient deficient blocks, and complete nutrient block (N2P2K2) as the fertilized block to estimate the N, P, K nutrient uptake efficiencies can produce a result that is more close to reality. N, P, K adjustment indexes can computed by the nutrient uptake efficiency values of N absent block, P absent block, K absent block respectively. There is a high correlation between objective yield and normal yield, and the relation can be nicely expressed by empirical equation. The correlations between objective yields and alkaline soluble N, available P, available K concentrations of soil are very insignificant. This is also true for the correlations between normal yields and alkaline soluble N, available P, available K concentrations of soil. Increasing N fertilization rate can result in increased N uptake efficiency for each unit of yield. In the case of P, K nutrients, the same kind of improvement can not be expected. However, N and P fertilization efficiencies decline while increasing N and P fertilization rates. The more surplus soil fertilization nutrients, the poorer efficiency soil fertility.