CHAPTER ONE

 INTRODUCTION

Pollution of agricultural soils is one of the most prevalent problems associated with the exploration and processing of petroleum hydrocarbon (Ayotamuno et al., 2006). Crude oil often known as “black gold” is a major source of income and support for Nigeria economy, (Eriemo, 2002). The high demand for petroleum products in form of cooking gas, gas oil, engine oil, lubricating oil, gasoline oil, aviation fuel, asphalt and coal tar means increased production and this eventually results in oil spills in the environment. Crude oil may be spill into the environment through accidental discharge, leakages from pipeline or flow-line, hose failure and perhaps sabotage, (Odu, 2000; Legborsi, 2007; Emuh, 2009; Emuh, 2011). Pollution occurs when a change in the environment adversely affects the quality of human life including soil and plants. Some Nigerian researchers like Oyedeji et al., (2012) noted that, pollution of soil with crude oil may hamper the normal photosynthesis and transpiration process leading to chlorophyll deficiency and quick death of plant.  Odu, (1987) reported that the ability of crops to germinate and grow on crude oil contaminated soil is dependent on the level of pollution as well as the concentration of the crude oil. Similarly, Udo, (2008) observed that, the higher the pollution, the more destructive it is to the plants. In low level of spillage (e.g. 1%), germination may be impaired due to lack of moisture and hardening of soil structure. At high contamination, seeds rotting will take place as a result of seeping of crude oil into the seeds through the other intergument. Oil pollution of soil leads to build up of heavy metals such as (lead, zinc, nickle, copper, manganese, cadmium) etc. in soils and these elements are eventually translocated into plant tissues (Vwioko et al., 2006). Although some of the heavy metals at low concentrations are essential micronutrients to plants, but at high levels, they may cause metabolic disorders and growth inhibition for most plants species (Fernades and Henriques, 1991). In a related view Yao et al., (2003) reported that Heavy metals does not only results in adverse  effects on various parameters relating to plant quality and yield but also caused changes in the size, composition and activity of the microbial activities. The uptake of Heavy metals by plants and accumulation in the food chain is a serious threat to both animal and human health (Sprynskyy et al., 2007). Heavy metals are toxic in human body and they accumulate in the soft tissue. High level ingestion of toxic metals has undesirables effect on human which becomes obvious only after several years of exposure to it. Pollution of the environment by crude oil is becoming prevalent across the globe. Although studies have been conducted on oil pollution effects on crop plants and trees species, (Anoliefo and Vwioko, 1995; Agbogidi 2009a; Agbogidi, 2009b); there is paucity of documented information on the effects of crude on pollution on the growth parameters of Jatropha curcas. It is against this background that a study as this was embarked upon

• Objectives of the Study

The objective of this study was to determine the effect of crude oil pollution on growth parameters of jatropha (Jatropha curcas)

Specific objectives of this study were to: 

1. Determine the effect of different levels of crude oil pollution on the growth parameters of Jatropha curcas.
2. Determine the fertility status of crude oil polluted soil.