Pollution of the soil with
petroleum products is associated with soils around industrial sites and in
areas where petroleum and natural gas are extracted (Adam et al., 2002; Clark,
2003). The processing and distribution of petroleum hydrocarbons as well as the
use of petroleum products lead to contamination of soil (Ayotamuno et al.,
2006).Moreover, accidental spills caused by pipeline leakages and ruptures and
accidents during transport have been reported (Ogbo, 2009).
Contamination of the soil environment can
limit its productive function, upset metabolic activity, unfavourably affect
its chemical characteristics, reduce fertility and negatively influence plant
production (Gong et al., 1996; Torstenssen et al., 1998; Wyszkowska and
Kucharski, 2000; Wyszkowski et al., 2004; Wyszkowski and Wyszkowska, 2005).
Diesel is a mixture of hydrocarbons with approximately 30% n-parafin,
45% cycloalkanes and 25% aromatics (Frankenberger and Jahanson, 1982; Speight,
1992, 2007). It also contains sulfur, nitrogen and oxygen in low concentrations
as well as metals such as lead, nickel, sodium, calcium, copper and uranium
(Posthuma, 1970). In Nigeria, most of the terrestrial ecosystem and shorelines
in oil producing communities are important agricultural land under continuous
cultivation. Crude oil pollution cause damages to soil condition of these
agricultural lands, microorganisms and plants (Onuoha et al., 2003). Diesel oil
can cause chronic or acute effects in the plants. In addition to direct and
indirect toxicity, diesel causes interference in the hydrophilic relations of
the plants. This interference, accompanied by the anaerobic and hydrophobic
conditions, has been found to be the most important effect of diesel
contaminated soil on seed germination and plant growth (Racine, 1994).
Many authors have reported a
lower rate of germination in soil contaminated by crude oil or petroleum
products (Amakiri and Onofeghara, 1984; Adam and Duncan, 1999, 2002; Vavrek and
Campbell, 2002; Achuba, 2006; Smith et al., 2006, Sharifi et al., 2007; Korade
and Fulekar, 2009; Ogbo, 2009). According to Baker (1970) and Adam and Duncan
(2002), petroleum hydrocarbons may form a film on the seed, preventing the
entry of oxygen and water. Achuba (2006) reported that crude oil inhibited the
activities of amylase and starch phosphorylase thereby affecting the
assimilation of starch by germinating cowpea seedlings.
Contamination of the soil with diesel oil limits the available soil nitrogen
and phosphorus, and also causes carbon-nitrogen ratio imbalance in the affected
soil (Roy et al, 2013). The overall consequence is reduced plant growth
resulting from direct toxic effect on plants and unsatisfactory soil condition
due to insufficient aeration of the soil (Nwaogu et al, 2006; Das and Chandran,
researches have been carried out on different organic wastes. Some of these
studies include the investigation on the effect of nutrient amendments of
diesel oil polluted soil on plant height, leaf area and leaf numbers of
eggplant (Solanum melongena) were soil samples were polluted and amended
separately with different weights of poultry waste, pig waste, cow dung and
inorganic fertilizer (Akujobi et al, 2011) and also the effects of non-sterile
and sterile abbatoir effluent on microbial degradation of diesel oil in soil
were evaluated (Umanu and Owoseni, 2013).
requires a large quantity of major nutrients like Nitrogen (N), Phosphorus (P),
and Potassium (K) for better growth and yield. A soil amendment is any material added to a soil
to improve its physical properties, such as water retention, permeability,
water infiltration, drainage, aeration and structure (Davis and Wilson, 2005). The application of pond wastewater as a fertilizer and
soil conditioner has not been widely reported.
The application of pond waste water could be a
very attractive proposal. This study was conducted to investigate the effect of
pond waste water on the growth and metabolism of cowpea seedlings grown in
diesel contaminated soil.
Significant of Study
attempts to exploit pond waste water as an organic fertilizer actively involved
in the remediation of diesel polluted soil. Local farmers with minimal or no
access to inorganic fertilizer in the Niger Delta area of Nigeria could benefit
from this research due to the fact that pond waste water is readily available
and is a cheap source of organic fertilizer. Also, the issue of proper ways of
disposing this pond waste water could be cocktailed with this research.
Scope of Study
study investigated the effect of pond waste water on both biomolecules and metabolism
parameters of cowpea seedlings grown in diesel contaminated soil. The
biomolecules include protein, glucose, amino acid, total sugar, total
chlorophyll, chlorophyll a, b and beta carotene while the biochemical
parameters determined include glucose – 6 phosphate dehydrogenase, ? amylase,
phosphorylase, succinate dehydrogenase.
1.4 Aims and
aim of the study was conducted to investigate the effect of pond waste water on
the growth and metabolism of cowpea grown in a diesel contaminated soil.
specific objectives of this study are to highlight:
the ameliorative effect of pond waste water on diesel induced alterations
of the metabolism of macromolecules in cowpea seedlings.
the ameliorative effect of pond waste water on diesel mediated oxidative
stress in cowpea seedlings.