Assessment of Physico-Chemical and Heavy Metals Properties of some Agricultural Soils of Awing-North West Cameroon

Abstract

This research work was aimed to assess the quality of agricultural soils of Awing-North West Cameroon by elucidating some physicochemical properties and heavy metals in the soils. Agricultural yields in Awing have witnessed a decline in recent years and farmers have repeatedly used fertilizers to improve on their agricultural yields. It is thus important to test the soil in order to ensure not only high productivity but its quality as well and suggest methods to increase agricultural yields, while preventing soil and water pollution. Twenty soil samples were randomly collected from four sites, Achialum, Meupi, Nepele and Ala'amiti, in Awing and analysed for physicochemical and heavy metal properties using standard methods. Results showed that all the soils had low bulk densities (0.76-0.89 g cm -3 ), low pH values (4.1-6.0), low electrical conductivities (0.02 -0.11 mS cm -1 ), low available phosphorus (1.55-14.26 mg kg -1 ) and the soil textural class was dominated by loam. The mean available concentrations of heavy metals ranged from 0.24-2. 73, 0.64-5.13, 13.79-34.51, 29.45-92.27, 0.00-0.80, 0.24-4.54, 0.68-1.39, 0.30-0.47 mg kg -1 for Zn, Cu, Mn, Fe, Pb, Ni, Cr and Cd respectively. Results of heavy metal analysis showed that the soils were contaminated to different levels (above FAO/WHO limits) by the different heavy metals. Natural origins, fertilizer application and domestic waste were identified as the major sources of heavy metals in the soils. Future research should focus on the development of methods to quantify lime-enhanced mobilization of nutrient ions and lime-induced immobilization of heavy metals in these soils.

An assessment of heavy metal exposure risk associated with consumption of cabbage and carrot grown in a tropical Savannah region

“…Where, Cn = average concentration of heavy metal measured in the soil; Bn= average geochemical background concentration of the same heavy metal (Mofor et al, 2017), 1.5 = background matrix correction factor due to lithogenic and anthropogenic influences.…”

“…where Cm = measured concentration of heavy metal in the soil and Bm = local background concentration value of the heavy metal (Mofor et al, 2017). The extent of heavy metal accumulation from soil by the vegetables was determined using the heavy metal transfer factor (TF) as described by Cui et al (2004).…”

“…As, Cd and Fe were found to be higher in the soils than their permissible limits by Food and Agricultural Organization/World Health Organization (2007). Very high concentrations of total and available Fe could be from the soil parent materials which are natural sources of Fe in the soils in Santa (Mofor et al, 2017). According to Ruqia et al (2015), excess amount of Fe more than 10 mg/kg in human blood causes rapid increase in pulse rate, coagulation of blood in blood vessels, hypertension and drowsiness.…”

“…Most studies carried out in Santa have dwelt on characterizing the soil properties of some agricultural systems in Awing (Santa) and the determination of surface water quality of some of the streams running through these large agricultural farms (Mofor et al, 2017;Okha, 2016). These results indicate that the excessive use of agrochemicals have altered not only the soil structure but also the water quality of some of the streams running through these farms.…”

Assessment of Physicochemical and Heavy Metal Properties of Groundwater in Edéa (Cameroon)

“…Exposure to Lead can result in neurological complications especially in children [44,45]. The high content of Manganese observed in some boreholes could be attributed to the acidic nature of the studied water as acidity increases solubility of Manganese [46].…”