Use of Various Chelates as Soil Extractants

Abstract

Four chelating agents—DTPA, EDTA, AB-DTPA and six molarities of sodium gluconate (0.005M, 0.01M, 0.015M, 0.02M, 0.025M and 0.03M) were compared as extractants for Cu, Fe, Zn, Mn, Pb, Ni, Cr and Cd in 5 diverse soils collected at different locations surrounding Peshawar from 0-30cm depth. Soil samples were also analyzed for soil chemical properties. The data of chemical analysis showed that soil pH was alkaline in nature. Electrical conductivity values of soil samples showed that the samples were non saline. Organic matter was found deficient and medium in 40 and 40 % samples respectively. AB-DTPA was the most effective extractant for Cu, Fe, Mn, Pb, Ni, and Cr whereas EDTA was the most effective extractant for Cd and Zn. An increasing trend in extractability of the nutrient was observed with an increase in the molarities of sodium gluconate.

Keywords: DTPA, EDTA, AB-DTPA, soil pH, Electrical conductivity, mineral nutrients