Crude oil pollution effect on agricultural soil properties and germination of bean (<i>Vigna unguiculata(/i) L.) seed

Abstract

Crude oil pollution affects not only soil properties but also seed germination. The aim of this
research is to checkmate the effect crude oil pollution has on soil fertility, seed germination
and microbial activity. Two different agricultural soils from Ibeno and Otuocha collected by
composite sampling were used to conduct the study. The crude oil for carrying out the research was sterilized with a micron Chromafil CA/S % 45 syringe filters. The physicochemical analysis of the soil and its microbiological enumeration was done. This was followed by the artificial pollution of the soil with fresh crude oil. Soil’s physicochemical properties and microbiological enumeration were analyzed followed by the planting of bean seed son the polluted soil. Unpolluted soils was also planted and served as the control. The artificial pollution of the soils’ increased physicochemical properties like cation exchange capacity, selenium, mercury, arsenic, carbon and phosphorus in both soil. Some physicochemical properties like electrical conductivity, salinity, vanadium, zinc, cadmium, iron, manganese, copper, cobalt, nickel and nitrogen decreased in both soils. Water permeability was positive and became negative after pollution. Soil texture was bound and became loose after pollution. Other soil properties like pH increased in Ibeno soil but decreased in Otuocha soil. The number of microorganisms decreases after pollution. Statistically, cultivated beans germinated faster on unpolluted soil and appear healthier than polluted soil because of slow germination and a wrinkled appearance. This study shows that crude oil pollution has a significant effect on soil fertility, seed germination and microbial activity.