Effect of slow or controlled release fertilizer on nutrients absorption and yield in soybean plant

With slow or controlled release fertilizer，dry matter accumulation，partitioning，nutrients absorption and yield variation in the growing period of so ybean are investigated in pot experiments．The results show that dry matter accumulation during the growing period in all treatments is high than that of control，especially in the treatment of LP-40 and LP-70；however，only those of LP-40，LP-70 and LP-SS100A treatments are higher than control after pod-setting．The controlled release fertilizers with short releasing time have less effect on nitrogen absorption，while the long-time one may reduce the nitrogen absorption at the earlier stage．However the controlled release fertilizers can increase the absorption of K⁺ to a certain extent，but have no effect on absorption of P0₄^3-．LP-SS100A can increase its productivity by 21．9％ ，LP-70 and LP-180A can increase its productivity by 13．1％ and 12．2％ respectively．