No abstract

Soil contamination through oil spillage accumulates in the soil and affect plant growth. The study was conducted to examine the effect of spilled engine oil on soil nutrients and germination of seed in the in the Central region of Ghana. Ten samples were collected randomly from selected mechanic and fitting sites in the Elmina municipality. A randomized complete block design using three test crops was used to evaluate soil quality indicators such as N, P, K and soil pH on the polluted soil using standard methods. Maize recorded 3.67, 18.5 and 3.7% germination in contaminated soils from Aponkyedasoro, Nippon and Afitafum, respectively. Cowpea and sorghum recorded no germination in these soils. The three crops showed higher germination rates in the control soils, with the highest being recorded in sorghum (72.2%), followed by cowpea (70.4%) with the least being recorded in maize (66.6%). The results showed that nitrogen (N) level in the experimental soil was very low (0.065-0.075%) as compared to the control (0.115%) in this study. However, polluted soil from Aponkyedasoro, Afitafum and Nippon recorded a higher level of phosphorus (60.84-31.58 µg/g) and potassium (0.52-0.58 µg/g) than control (P=20.97 µg/g; K=0.43 µg/g) despite having a low germination rate. Copper, zinc, sodium and iron concentration were higher in the engine oil-polluted soil. The study revealed that the concentration of heavy metals and spilled engine oil in the soil has a higher effect on plant development; hence, public awareness should be created of its detrimental effect on the ecosystem.

Even though pesticides constitute a very essential component of improved and modern agriculture, the abuse of pesticides has brought substantial poisoning worldwide, especially in developing countries. This review investigates the possible sources by which people are exposed to pesticides worldwide and the impact on their livelihood. The group who often are exposed to these chemicals includes, farm workers, children, farmers, and family members who have direct link to the pesticide application sites as well as persons who are exposed to these pesticides through the domestic use of waterbodies and consumption of foodstuff or crops sprayed with these pesticides. Central to this review is the critical discussions of the different scientific research findings on health effects and risks related to pesticides usage. Again, organophosphates and organochlorines pesticides are found in most of the pesticide contaminated sites and can remain in soil and waterbodies for a longtime. This work has also provided cases of incidence of carcinogenicity in humans, as a result of pesticides use. We concluded that, breeding or developing insect tolerant or resistant crops may curb the profuse use of pesticides in agriculture.

In tropical soils, phosphorus adsorption is a major key process that controls its availability to crops. Phosphorus is one of the main essential plant nutrients required by the plant in large quantities. Plants absorb P either as the primary monobasic phosphate, H2PO4- ions or smaller amounts of the secondary dibasic phosphate, HPO42- ions and the phosphate ion, PO43-. Inadequate supply of phosphorus to the plant affects its potential yield nor cannot complete the reproductive cycle. Regardless of its importance to crop, it can also reduce more than 40 % of crop yield of the world’s cultivated land. Additionally, P levels in tropical soil are been depleted at a higher rate and according to some estimates from the literature reviewed there will be no P reserve in soil by the year 2050. Phosphate adsorption isotherm studies the interaction of the ions with the oxides and soil and also measure the adsorption capacity of soils. Application of P to crop in the form of fertilizers can be adsorbed by the soil but may not be available for plants restricted with specific adaptations. Application of P containing fertilizers can increase available P in the soil hence increase crop yield which can be used to feed the world’s rapid population growth.