Organic Manure Enhanced Phytoremediation of Crude Oil Contaminated Soils in The Niger Delta: The Potentials of Cowpea (Vigna Unguiculata) (Published)
In spite of frequent oil pollution, a cost effective, environmentally friendly and sustainable means of remediating polluted soils is yet to be discovered in the Niger Delta. This study, examined the effect of two rates of poultry manure (0 and 20 t/ha) remediating 0 and 5% oil in a 2x2x3 factorial, using cowpea (Vigna unguiculata) as possible phytoremediation plant. Two weeks after contamination, Total Petroleum Hydrocarbon (TPH) increased significantly (P<0.05) from 0.02 mgkg-1 to 125.1 mg/kg-1 and at eight weeks after remediation, TPH reduced from125.1 mgkg-1 to 91.86 mgkg-1 in the unamended contaminated soil and the poultry manure amended contaminated soil decreased significantly (P<0.05) to 73.08 mgkg-1. Soil pH increased significantly (P<0.05) from 5.34 to 5.80, two weeks after contamination and after eight-week of remediation, pH in the unamended contaminated soil increased to 5.85 and the amended contaminated soil increased to 5.97. Organic carbon increased significantly (P<0.05) from 1.15% to 2.32% after two weeks of contamination and eight weeks after remediation, increased to 2.45% in the unamended contaminated soil, and to 2.58% in the amended contaminated soil. Though oil contamination slowed germination, cowpea germination in the unamended contaminated soil recorded 60% while poultry manure amendment increased germination to only 66% indicating cowpea has phytoremediation qualities. However, poultry manure amendment increased cowpea germination energy. The study recorded no significant difference in cowpea germination percentage and growth parameters between the unamended contaminated soil and remediated oil contaminated soil indicating poultry manure application rate need to be increased.
Keywords: Organic Manure, Phytoremediation, Pollution, cowpea, crude oil
Effects of different Levels of Compost Manure on Upland Rice and Soil Chemical Properties in Asaba, Delta State, Nigeria (Published)
Field experiment evaluated effects of compost levels on growth and yield of upland rice, and soil chemical properties was carried out in Department of Agronomy Teaching and Research Farm, Delta State University, Asaba Campus in two cropping seasons. The compost was formulated with rice husk and cowdung at the ratio of 7:3, water was added during turning at weekly intervals for twelve weeks. It was applied at four levels: 0, 2.5, 5.0 and 10.0 t ha-1, while inorganic fertilizer was applied at 200 kg ha-1. The experiment was laid out in randomized complete block design with four replicates. Parameters measured were plant height, number of leaves, total leaf area, plant girth, dry matter, rice yield and soil chemical properties were soil pH, organic matter, nitrogen, phosphorus and exchangeable bases. Data were subjected to analysis of variance and means were separated with DMRT at 5% level of probability. The result shows that 10.0 t ha-1 of compost manure had highest plant height, plant girth, number of tillers, dry matter and rice yield at second season while the inorganic fertilizer had highest in all growth parameters in first season. All the levels improved the soil chemical properties than the inorganic fertilizer and 0 t ha-1. Therefore, 10.0 t ha-1 could be recommended for farmers in Asaba.
Keywords: NERICA, Organic Manure, Soil fertility, application rates, rice waste