AN ASSESSMENT OF THE EFFECTS OF CRUDE OIL POLLUTION ON SOIL PROPERTIES, GERMINATION AND GROWTH OF MAIZE (ZEA MAYS) USING TWO CRUDE TYPES - FORCADOS LIGHT AND ESCRAVOS LIGHT

摘要

The effect of crude oil pollution on soil properties, germination and height of maize (Lea mays) was investigated under natural environment in three separate pot experiments. Two crude oil types - Forcados light and Escravos light were used. In Experiment 1, the effect of crude oil application on germination using high pollution levels of 5, 15, 25 and 40 mL kg~(-1) of soil was assessed. In Experiment 2, the effect of crude oil application on maize plant height using the same pollution levels was assessed. The last experiment (Experiment 3) was used to test for the effects of crude oil application on maize plant height using lower levels of pollution (1.0, 1.5, 2.0 and 2.5 mL kg~(-1) of soil). Soil samples were collected before, during and after the experiment and analyzed for some physical and chemical properties. Results obtained showed variation in chemical properties of soil. % organic matter increased from 1.34 to 2.62% in polluted soils. Available P decreased from 15.00 ppm in control to between 7.34 and 5.42 in soils polluted with 'high' levels of crude oil. Statistical analysis of height data showed that crude oil inhibited the growth of maize at high pollution levels. High levels of pollution also inhibited germination and for Escravos light there was no germination at 40 mL kg~(-1) soil level of crude oil pollution.