Abstract

The purpose of this study is to determine the phosphorus status of soils of Tekirdag province that have different chemical and physical properties according to the Neubauer seedling method which is selected as a biological index method and to select the method which gives highest relationship from the 3 different chemical extraction methods (1- Water soluble P, 2- Soluble P in acid fluoride, 3- Soluble P in sodium bicarbonate) for determining the available phosphorus amount. For this purpose 26 samples of soil are collected from 0-20 cm depth in Tekirdag. The greenhouse study has been performed in accordance to the Neubauer seedling method and a completely randomized block desing with 3 replications. The rye (Secale cerale L.) has been selected as the test plant. In order to determine the most suitable chemical method, the dry matter yield, phosphorus content and total phosphorus uptake of the test plant has been taken as the biological (standard) criterion. No relationship has been found between any of the chemical extraction methods and dry matter yield of rye plant in this study. According to the research results, significant relationships have been found only with the water soluble phosphorus method and phosphorus content and total phosphorus uptake of the test plant (respectively r= 0.374*, r= 0.342). Method of P soluble in water is found to be the most appropriate method in determining the phosphor in soils of Thrace region.