EFFECTS OF FERTILIZING ON MILLET ROOT-SHOOT GROWTH,RHIZOSPHERIC SOIL ENZYME AND MICROBE IN IMMATURE SOIL IN NORTH CHINA

Immature subsoil of loess was used to study the effects of N,P,K and organic fertilizers on potted millet growth and rhizospheric soil enzyme with microbe system.The results showed that:(1) P was the primary original factor for soil fertility forming and crop growth;(2) Under the treatments of all the P-fertilizer,millet root-shoot growth was significantly better than that without P-fertilizer at the seedling stage,only applied N and K were even lower than CK,the effects of N,P,K on millet root-shoot growth was in order of P N K;(3) At the middle later stage,the effect of N,especially the combining effects of N,P,K appeared rapidly;(4) Under the treatments of all the P-fertilizer,millet yields and yield-structures increased significantly;(5) Single and enough quantity of only organic fertilizer application had good effect instantly in immature soil in the same year;(6) Strong root promoted the rhizospheric microbe to multiply rapidly and increased the rhizospheric enzyme activities,which in turn to benefit the root-soil system,and the normal yield level of millet was reached in immature soil in the same year.