Effect of sewage sludge on germination, growth and biomass yield of sorghum in calcareous soils

Effect of sewage sludge on germination, growth and biomass yield of sorghum crop was studied utilizing three calcareous soils and the sewage sludge at the rate of 0, 25, 50 and 75 Mg ha-1 in a pot experiment. The mean crop germination ranged between 77.5-97.5 percent and there was no significant reduction in germination due to sewage sludge application. Mean plant height ranged between 33.98-77.60 cm and the mean biomass ranged between 0.075-0.525 kg per pot in different sewage sludge treatments. The plant height and the biomass yield increased significantly with an increase in sewage sludge application. There was an increasing trend in plant height and total biomass yield in heavy textured soil than other soils. There was no significant effect of varying CaCO3 contents of soils on crop germination, plant height and biomass yield receiving different rates of sewage sludge. In conclusion, there exists an excellent potential for the use of sewage sludge not only as organic matter but also a promising source of plant nutrition for increasing the productivity of sandy calcareous soils in an arid environment. The research findings also highlighted the usefulness of sewage sludge and sewage waste for its utilization as organic matter for reasonable forage production as well as to minimize the expected environmental hazards from land disposal of these sewage wastes.