THE EFFECTS OF SOIL AMENDMENTS ON THE GROWTH AND YIELD PERFORMANCE OF COWPEA (VIGNA UNGUICULATA CV. IFE BROWN) SOWN IN A PETROLEUM HYDROCARBON-POLLUTED SOIL

The present study was on the phytoassessment of a waste engine oil (WEO)-polluted soil after amendment, using Vigna unguiculata cv. Ife Brown. Top (0 - 10 cm) constant measured into buckets. WEO poured and thoroughly mixed to obtain 2.5% w/w oil-in-soil concentration. Polluted soils were with manure (MN) and/or sawdust (SD) at 10% respectively. However, when more than amendment applied, they both added together in equal proportions make substrate soil. Urea (UR) also applied 4g/kg treatments available during included, polluted (PS), PS+UR+SD+MN, PS+SD+MN, PS+UR+MN, PS+UR+SD, PS+MN, PS+SD PS+UR an unpolluted (UPS). entire set up or control left open shade for 3 months without mechanically disturbing Thereafter status cowpea. Results showed significant reductions heavy metal contents After three planting, copper ranged from 4.8 6.4mg/kg while lead (Pb) 0.89 1.64mg/kg amended compared 2.08mg/kg unamended but sowing. Comparatively, cow dung had relatively less hydrocarbons other amendments combinations. that there depressed vegetative growth yield performance cowpea oil-polluted Soil however enhanced plant survival. Estimated grain lowest not (222.3kg/ha), 956.04kg/ha highest PS+MN (147878.35kg/ha).