Effects of Crude Oil Pollution on Soil Physico-Chemical Properties in Crude Polluted Soil of Arachis Hypogea and Citrullus Vulgaris Potted Plant

The effects of crude oil pollution on the Soil physico-chemical properties in crude polluted soil in potted plant of Arachis hypogea and Citrullus vulgaris were investigated in a green house under controlled environmental condition. Eight wide open black polythene bags, each filled with 10 kg of 2 mm sieved soil was used. Treatment of the soil was carried out by adding varying concentrations of crude oil raging from 0, 0.5, 2 and 5 % into soil samples contained in polythene bags. Each concentration of crude oil was added to each soil sample in each bag and was thoroughly mixed using gloved hands. The Eight polythene bags were separated into two groups of four bags each. Thereafter, 30 seeds of groundnut (Arachis hypogeal L.) were planted into each of the four polythene bags with soil sample treated with varying concentrations of crude oil and 30 Seeds of Egusi melon (Citrullus vulgaris L.) were planted to each of the other four polythene bags of soil sample treated with varying concentrations of crude oil  (four bags for groundnut and four bags for egusi melon). The result revealed that, at different pollution levels, crude oil pollution changes soils physical and chemical properties. The type of plants, different plants’ growths and time were also observed to co-influence the changes in soil properties by the crude oil pollution. The soils were also observed to stick together with increasing crude oil pollution. This coagulatory effect of increasing crude oil on the soil binds the soil particles into water impregnable soil block, which impaired water drainage and oxygen diffusion. Crude oil pollution of 2 and 5 % significantly reduced the germination and growth of the Citrullus vulgaris (melon) while in Arachis hypogeal (groundnuts), germination increased with increase in crude oil contamination of up to 5 %. At 5 % oil level, all the seeds of groundnut germinated but with time there was a reduction in the growth parameters possibly due to the coagulatory effect of increasing crude oil on the soil, binding the soil particles into water impregnable soil block which impaired water drainage and oxygen diffusion. Again, the tolerance exhibited by groundnuts could possibly be linked to its ability to fix nitrogen. Melon (Citrullus vulgaris L.) and physicochemical properties of the soil was investigated in the green house at the Department of Crop/Soil Science of the Rivers State University, Port Harcourt, Nigeria. Planting was done in a wide open black polythene bag filled with 10 kg of 2 mm sieved soil. Eight polythene bags, each per crude oil concentration, were used (four polythene bags for groundnut and four for melon). Treatment of the soil was carried out by adding varying concentrations of crude oil, namely 0, 0.5, 2 and 5 % into soil sample in the polythene bag. Each bag was thoroughly mixed using gloved hands. Thirty seeds of groundnut (Arachis hypogea L.) were planted into each of the four polythene bags with soil and thirty seeds of melon (Citrullus vulgaris L.) were planted into each of the other four polythene bags of soil sample treated with varying concentrations of crude oil. The result indicated that crude oil pollution of 2 and 5 % significantly reduced the germination and growth of the melon, while in groundnut, germination increased with increase in crude oil pollution of up to 5 %. At 5 % oil level, all the seeds of groundnut germinated but with time there was a reduction in the growth parameters possibly due to the coagulatory effect of increasing crude oil on the soil which bound the soil particles into water impregnable soil block, which impaired water drainage and oxygen diffusion. At different pollution levels, crude oil pollution changes soil physical and chemical properties. The lipid, protein and carbohydrate contents of both seedlings increased with increase in oil concentration of up to 5 %. There was a reduction in the growth parameters possibly due to the coagulatory effect of increasing crude oil on the soil, binding the soil particles into water impregnable soil block, which impaired water drainage and oxygen diffusion.