IMPACT OF PRESSMUD AS ORGANIC AMENDMENT ON PHYSICO-CHEMICAL CHARACTERISTICS OF CALCAREOUS SOIL

In order to asses the impact of pressmud (a waste by-product from sugar factories) as organic amendment on physico-chemical properties of calcareous soil, a field study was conducted at the experiment station of Faculty of Agriculture, Gomal University, D. I. Khan during 2007-2008. The experiment was laid out in a Randomized Complete Block Design, having four replications. The treatments were (1) control, (2) NPK (30:60:45 kg ha^-1), (3)2 t ha^-1 pressmud, (4) 4 t ha^-1 pressmud (5) 6 t ha^-1 pressmud, (6) 10 t ha^-1 pressmud (7) 15 t ha^-1 pressmud (8) 20 t ha^-1 pressmud. The soil was calcareous (time 6.3%), (pH 8.1) and low in organic matter content (8 g kg^-1). The pressmud used in this experiment was rich in micronutrients such as Cu, Fe, Mn, Zn and also contained sufficient amount of Ca, Mg and Na. Therefore, the addition of pressmud increased the available P, S, K, Fe, Mn, Zn and Cu content in soil in addition to increase in total porosity of soil. On the other hand, there was small increase in ECe , and small decrease in bulk density and pH of the soil as a result of increasing levels of pressmud application. It was concluded from the study that the application of pressmud @ 15 to 20 t ha^-1 would be the most suitable dose for improving the physico-chemical properties of calcareous soil.