A study on quantifying the productivity of spent oil contaminated soil amended with organic wastes using productivity index (PI) was carried out at the Teaching and Research Farm of the Faculty of Agriculture and Natural Resources Management, Ebonyi State University, Abakaliki. The study involved a modification of Pierce et al. productivity index model with simultaneous exclusion of sufficiencies for aeration and electrical conductivity. The applicability and validity of the modified Pierce et al. productivity index model were determined using maize as a test crop. Result showed highly significant (r=0.96 at P<0.01) relationship between PI and grain yield of maize. The general mean PI and grain yield of maize were 0.32 and 0.94 tha-1for the treatments. The mean productivity indices with grain yield of maize were 0.20 and 0.50tha-1, 0.40 and 1.2otha-1, 0.26 and 0.80 tha-1 and 0.42 and 1.3tha-1 for control, burnt rice husk dust, unburnt rice husk dust and saw dust amended soils, respectively. The burnt rice husk dust which had highest prediction of 0.58 also predicted highest grain yield of maize of 2.2tha-1. The grain yield of maize followed productivity index predictions. Organic wastes could be recommended for attenuating problem of spent oil contamination of soil in Abakaliki.
Keywords: Amended, Contamination, Organic wastes, Productivity, Quantifying, Soil, Spent oil.
