Effect of Forest-Incubated Composts on Crude-oil Soils for Zea mays, L. Cultivation in Delta State, Nigeria

This study examined the potential of forests to provide essential composting edaphic conditions that enhance the microbial density and public health for degradation of crude-oil contaminated soil. Legume (L), woodshaving/poultry dropping (WD), cow dung (CD), legume + woodshaving/ poultry dropping (LWD), legume + cow dung (LCD), woodshaving poultry dropping + cow dung (WCD), and legume + gut of ruminant animals (LGA) were incubated at 3, 6 and 8weeks periods in Forest Reserve to produce compost teas and slurries. Crude oil-contaminated soils were then inoculated with compost formulations and soil restorative capacity was evaluated using Zea may, L. seeds in a-8 x 3 x 2 factorial experiment. Collected data of emergence at 1, 2, and 3 weeks after sowing, stand counts at 4 and 8WAS, plant heights, and leaf areas at 10 and 12WAS were subjected to analysis of variance and Pearson correlation matrix. Results showed that total petroleum hydrocarbon decreased with the incubation period for all treatments to 8 weeks. Stand count of maize for the 6weeks incubated compost was LGA (77.5%) > WCD (52.5%) > LCD (45.0%) > LWD (35.0%) > WD (25.0%) > CD (30.0%) > L (25.0%) at 4weeks after sowing with similar trend in plant height and leaf area at 12 WAS. Soil treated with 6weeks incubated compost significantly correlated with plant emergence as PE3-8 (r =0.83), PE6-8 (r = 0.83) as well as plant height HT-3 (r = 0.88) and HT-8 (r=0.93) at 12 WAS.