DETERMINATION OF SUITABLE CHEMICAL EXTRACTION METHODS FOR AVAILABLE IRON CONTENT OF THE SOILS FROM EDIRNE PROVINCE IN TURKEY
2002, 3 (3) p. 255-262
The aim of this research was to determine the available iron (Fe) content of the soils of Edirne Province and the most suitable chemical extraction method. Eight chemical extraction methods (0.005 M DTPA + 0.01 M CaCl2 + 0.1 M TEA; 0.05 M HCl + 0.012 M H2SO4; 1 M NH4OAc (pH: 4.8); 0.01 M EDTA + 1 M NH4OAc; 1 M MgCl2; 0.01 M EDTA + 1 M (NH4)2CO3; 0.005 M DTPA + 1 M NH4HCO3 and 0.001 M EDDHA methods) and six biological indices (dry matter yield, Fe concentration, Fe uptake, relative dry matter yield, relative Fe concentration, relative Fe uptake) were compared. Biological indices were determined with Barley (Hordeum vulgare L.) grown under greenhouse conditions. At the end of the experiment, the highest correlation coefficients (r) were determined to be between the 0.005 M DTPA + 0.01 M CaCl2 + 0.1 M TEA method and the biological indices and between the 0.005 M DTPA + 1 M NH4HCO3 method and the biological indices. The correlation coefficients (r) for the 0.005 M DTPA + 0.01 M CaCl2 +0.1 M TEA method were r=0.621**; r=0.823**; r=0.810**; r=0.433**; r=0.558** and r=0.640** and for the 0.005 M DTPA + 1 M NH4HCO3 method r=0.618** ; r=0.520**; r=0.679**; r=0.521**; r=0.492** and r=0.641**, (**:p<0.01) respectively. These extraction methods, among all the methods tested were suggested for the determination of available Fe content of Edirne Province soils.