The effect of burnt and un-burnt land on soil physicochemical characteristics in Ekeya-Okobo Local Government Area, Akwa Ibom State, Nigeria

Slash and burn method of land clearing is an integral part of the traditional farming system widely used as a means of land clearing to pave way for crop production in southern Nigeria. This management has both beneficial and detrimental effects on soil and its properties. Based on this, effects of fire on soil quality dynamics was examined during slashing and burning of the plots at the depths ranging between 0-15, 15-30cm respectively. The soil sample point s was chosen using a simple random sampling and the soil sampled were analyzed for the selected physical and chemical characteristics. ANOVA was used for significance difference between soil from burnt and unburnt plots using statistical package for social science (SPSS), and significant means were compared using Duncan multiple range test. Paired t-test was used to compare means of the unburnt and burnt plots. At the depth of 0-15cm, the unburnt plot recorded decrease in pH(H2O) 5.6, pH ( KCI)4.9, increase in sand, silt, K and base saturation, while burnt plotrecorded increase in clay, SOC, SOM ,TN , Avail P., Ca2+, Mg2++, Na+ and EC (H++Al3+). At the depth of 15-30cm, unburnt plot recorded low pH in H2O and Kcl, silt, Mg and EC while burnt plot recorded highest values in other selected parameters than unburnt plot. Between the two plots sampled, changes of physical and chemical parameters were significant at the P :< 0.05 probability level, (Ftab = 4.60 Fcal= 1.597Ω 1.6). Based on this, there is a need for environmental education for farmers in the area to know the implications of burning of farmland on soil ecosystem and environment as a whole for soil sustainability that will boost food production.Keywords: Burnt and un-burnt, Soil, physiochemical, agriculture, soil acidit

Assessment of Heavy Metal Concentration in Soil Impacted Mining-Overburden in Enyigba, Abakaliki, Ebonyi State, Nigeria

This study assessed the concentration of selected heavy metals (Lead and Zinc) from surrounding soil of Royal Salt mining company, Enyigba in Abakaliki LGA, Ebonyi State. Soil samples were collected from nine (9) different locations at depths of 0-15 and 15-30cm. Two (2) samples were collected from each of the nine locations, making it total of eighteen (18) samples. Soil analysis carried out were particle size distribution, pH, available Phosphorus, total Nitrogen, Organic Carbon, organic matter, Calcium, Magnesium, Potassium, Sodium, exchangeable acidity, Aluminium, effective cation exchange capacity, base saturation and two selected heavy metals, Lead (Pb) and Zinc (Zn). Results shows that heavy metals were highest in soil around the disposal site of mine waste. The highest value of Pb and Zn was recorded on tailing down (TD) 14.82 and 25.33mg/kg at 0-15cm depth, 7.22 and 18.93mg/kg at 15-30cm depth respectively. The accumulation of Pb and Zn at the mining site (TD) may be due to mining activities, civil, industrial/anthropogenic activities going on around the site. This study recommends regular monitoring of heavy metal  concentration in soil within the mining site and their disposal site in order to conform to international standards set by the WHO. Keywords: Abakaliki, Enyigba, Lead, Royal Salt Limited, Zin

Assessment of soil pH and heavy metal concentrations in agricultural land impacted with Medical Waste Incinerator (MWI) Flue Ash (FA) in Abia State, Nigeria

This study focused on the effect of heavy metals being introduced into soils through medical waste incinerator flue ash by collecting soil samples at different depths and distances to determine soil pH, Cu, Zn, Cr, Cd, Pb and Mn contents using standard methods and multivariate tools for data summary. Mean soil pH values ranged: 5.2 – 6.2 > 4.8 of control due to flue ash as a liming agent and farming practices respectively, with low pH that encourages mobility and absorption of heavy metals in ecosystems. Heavy metals in incinerator site(mgkg-1) ranged:2.00105 ± 0.00-2.09050 ±0.00; 4.0011±0.00-12.3250±0.00; 6.0405±0.01-8.0150±0.01; 4.0150±0.00-7.0805±0.07; 0.2100±0.01-1.0950±0.01; 0.00±0.00-0.001100±0.00; 0.0305±0.01-0.1150±0.00 for Cu, Zn , Mn, Cr, Cd and Pb respectively, with control 0.55 ± 0.01-1.25 ± 0.01;1.25 ± 0.01-1.45 ± 0.01; 13.15 ± 0.07-14.15 ± 0.07; 0.02 ± 0.01; 0.00 ± 0.01-0.03 ± 0.01; .54 ±0.01-.54 ± 0.01 for Cu, Zn , Mn, Cr, Cd and Pb respectively .Metals were in order of: Cd≤ Cu ≤Pb≤ Cr≤Mn≤ Zn(LSD0.05). Result revealed that Cr, Cd and Pb were below the limits for agricultural soil by FAO, and were higher at 50-100m and decrease farther from incinerator. Negative correlation exists between Cr and Zn; Zn and Cu due to farming practices, Mn, Cd recorded positive correlation due to incinerator flue ash. Factor 1 loaded Cu positively, Cr, Pb, Mn, and Zn negatively loaded. Factor 2, exception of Cr, Cd, Pb, and Mn loaded negatively due to flue gas and lithogenic respectively, C/PI indicated soil being slightly, moderately to severely contaminated respectively. I-geo indicated uncontaminated to moderately contaminated, showing that heavy metal contaminations of soils is minor.Keywords: Element, Incineration, Flue Smoke, Soil Acidity, multivariate analysi