تاثير اسيدهاي آلي بر افزايش قابليت جذب و برداشت فسفر از ريزوسفر گندم

Organic Acids and Availability of the Rhizosphere Phosphorus and Its Uptake by Wheat

This study was conducted to determine the importance of organic acid type and concentration in the rhizosphere of wheat plant (Triticum aestivum L.) and its effects on 33P uptake by roots. Organic acids such as citrate and oxalate are implicated in rhizosphere processes, including nutrient acquisition. A single wheat plant was grown in soil-filled rhizosphere microcosms and allowed to pass through a KH233P04 labeled of soil. Forty- -1 "2 eight hours after P injection, citrate and oxalate at concentrations of 1 and 10 mM were injected into the microcosms at the same location every day over a period of 4 days. Oxalate resulted in about 2-fold enhancement in plant j3P accumulation, but citrate had no such effect. High mineralization of citrate was observed in comparison with oxalate. It seems that due to more mineralization of citrate, 33P uptake was prevented. As a result, organic acids cause an increase in P mobilization and P uptake by plant is enhanced.