Effect of Fertilization on Growth,Dry Matter Accumulation,Nutrient Uptake and Distribution in Sorghum

Based on 3414 test,sorghum(Sorghum bicolor(L.) Moench) cv.Jinza 12 was used to investigate the effects of different combination application rates of N,P and K on growth,dry matter accumulation,nutrient uptake and distribution in different parts of plant under field experiment conditions.The experimental results showed as the following:When no N,P or K was applied,the root volume,plant growth and yield were the lowest among the 14 treatments,and application of any two of the three N,P or K,sorghum growth would be remarkably promoted;When any two of these three were designed as the optimum rates,P would significantly promoted grain yield whereas no such effect of K was observed;The dry matter mainly accumulated from shooting stage to heading stage,the maximum dry matter accumulation was obtained at the maturity stage.The dry matter accumulation at all stages of sorghum plants with fertilization was always higher than those without fertilization.The dry matter accumulation at maturity stage increased 19.77%,as compared with the control.The dry matter partitioning was mainly in the leaves and stems of the sorghum plants.Fertilization did not influence the proportion of dry matter partitioning.The order of the nutrient accumulations and the proportion of nutrient partitioning was KNP in sorghum plants.The nutrient accumulations and the proportion of nutrient partitioning were not the same at different stages.The nutrients of N,P and K were mainly partitioned in leaves and stems.The order of the proportion of nutrient partitioning was PNK in the grain sorghum head.The nutrient absorption ratio of N,P2O5 and K2O was 1∶0.32∶2.22 in whole plants with fertilizer supply at maturity stage.It showed similar trend in the nutrient absorption ratio of N,P2O5 and K2O in plants with and without fertilizer supply at different stages.