Improvement of Soil Physicochemical Properties and Heavy Metal Reduction by Integrating Vermicompost and NP Fertilizer in Industrial Zone at Dukem, central Ethiopia

Abstract

Soil nutrient deficiency, alkalinity and heavy metal toxicity are the most serious constraints for soil fertility and crop productivity around industrial zone in Dukem, central Ethiopia. Integrated nutrient man- agement is essential to resolve this problem there by increasing the productivity of the soils. Therefore, trials were run in greenhouse to evaluate the response of selected soil physicochemical properties and heavy metals to mineral NP and vermicompost fertilizer application. Three rates (2.5, 5.0, 7.5 t/ha) of vermicompost with three rates of mineral NP (25, 50, 75%) and control treatment were arranged in randomized complete Block design (RCBD) with three replication. The results revealed that integrated application of 7.5 t/ha vermicom- post and 75% NP increased the exchangeable Ca, Mg, K, cation exchange capacity, organic carbon, total N and available P by 341.51, 78.71, 133.3, 26.18, 33, 54.28 and 172.38%, respectively as compared to the control. Whereas, heavy metals Cr, Pb, Cd and Ni decreased by 80.74, 81.25, 79, 44 and 46.41%, respectively and exchangeable sodium and pH were also decreased at the same treatment. However, sole mineral NP fertilizer increased heavy metal availability. Therefore, the combined application of 7.5 t/ha vermicompost and 75% NP was found to be the best for the enhancement of soil physicochemical properties and reduction of heavy metals in study area and other similar agroecologies