Investigation of soil fertility at a remote site in Karachi,Pakistan

This study reveals chemical and physical properties of soils collected from a remote site at karachi,pakistan. altogether 23 parameters were determined. out of 12 soil samples 11 were categorised as sand or sandy loams,ph varied between 7.35-8.49,density ranged between 1.61-2.39 gm/cm3,the conductivity of 1:2 water extracts varied up to a great extent i.e.,between 0.437-16.47 ms/m3. sodium (na) contents were higher in ammonium acetate extract when compared with 1:2 water extract. the bicarbonate (hco 3) contents were ranged between 0.17-1.73 ppm. the organic matter contents were low (0.81-2.21%); these soils were also deficient in their macronutrient contents. specifically,the ranges of nitrogen (n),phosphorous (p),potassium (k),calcium (ca),magnesium (mg) and sulphur (s) were 0.04-1.16%,0.25-15.99 ppm,4.40-135.89 ppm,0.001-0.199%,0.001-0.019% and 0.01-0.143%,respectively. heavy metals were determined in diethylene-triamine- pentaacetic acid (dtpa) extracts and the levels of iron (fe),copper (cu),manganese (mn),and zinc (zn) in these samples were 1.86-32.80 ppm,1.68-7.69 ppm,16.51-75.28 and 0.25-20.75 ppm,respectively. toxic heavy metals,lead (pb) and nickel (ni) contents were also estimated and their concentration was found low ranging between 0.91-5.63 ppm and 0.32-1.26 ppm,respectively.