The uptake of phosphate by barley plants from soil under aseptic and non-sterile conditions

Abstract

The uptake of phosphorus by barley plants growing in soil has been compared in the presence and absence of microorganisms. The soil chosen for study was basaltic loam which earlier investigations had shown required the addition of supplementary phosphate to obtain successful growth of plants. Despite a rapid turnover of the phosphorus in microorganisms as a result of death and lysis, less was absorbed by plants grown under non-sterile conditions causing a considerable reduction in the yield of dry matter. These microbial effects were obviated by the addition of a small quantity of KH 2PO 4 (0.15 m-equiv/500 g soil). In this soil therefore, competition appears to exist between microorganisms and plants similar to that demonstrated previously in water culture.