Effect of Zn and ABT on root growth and the phosphatase and pH at rhizosphere of maize

A field rhizo-bag experiment was conducted to study the effect of Zn and ABT (grow-root powder No. 4) on maize roots growth and rhizosphere microecology during five growth periods in calcareous soil. The results showed that the distribution of maize root was "S" form with five growth periods, and the root length and volume reduced during the later growth stage. Application of Zn and ABT promoted the length of root and increased root surface area contacted with soil, retarded senescent speed, and improved rhizosphere microecology. pH was lower and phosphatase activity significantly higher in rhizosphere of maize than in non-rhizosphere. The acid phosphatase was higher in rhizosphere with all treatments during maize growing stage, and the alkaline phosphatase with Zn, ABT and Zn+ABT treatments was higher at heading stage of maize. Application of Zn and ABT could improve maize rhizosphere microecology, and found for effective utilization of phosphorus from soil and fertilizer.