Quantifying the Stock of Soil Organic Carbon using Multiple Regression Model in a Fallow Vegetation, Southern Nigeria

Identifying ecological variables that explain significant variation in the stock of carbon is indeed one way of sustaining its concentration in the soil. The stepwise multiple regression model was employed to identify ecological variables that explained significant variation of carbon in fallow soils. Using fallow genealogical cycles of 1st, 2nd, 3rd, 4th and 5th generations, soil and vegetation variables from 30 sampling plots were collected and subjected to linear regression analysis. The analysis generated three predictive models. The first and second models significantly (p<0.01) explained 78% (R2 = 0.78) and 87% (R2 = 0.87) of the variability in soil organic carbon (SOC), while the third (full) model significantly (p<0.01) explained 89% in the variability of carbon stock (R2 = 0.89) with vegetation cover, available phosphorus and total nitrogen being the most significant predictor variables. The full model was upheld because it identified three significant ecological variables that explained increased variability in the stock of SOC. The study suggested that management of the ecological variables identified in the full model which indeed were associated with the abundance of woody and herbaceous vegetation would not only increase the stock of SOC in the soil, but reduced its concentration in the atmosphere. For this to be feasible mostly in the present changing climate, healthy forest and land management practices, such as the creation of vegetal buffer zones around farmlands, zero-tillage practice, mulching, retaining of forest slash and crop residues, fertilizer application, elongation of fallow periods, and tree planting initiatives in degraded ecosystems were encouraged.Keywords: Stepwise Regression, SOC, Healthy Forest and Management Practices Fallow Genealogy,Woody Perennial Tree Species, Fallow Elongatio

Effects of Fallow Genealogical Cycles on the Build-up of Nutrients in Soils of the Cross River Rainforest, South-Southern Nigeria

The study examined the effect of fallow generational cycles on the buildup of nutrients in the soil. Fallow sequence of 1st, 2nd, 3rd, 4th and 5th generations were studied. The quadrat approach of sampling was employed to collect soil samples (surface and subsurface) from five plots of 10m x 10m across the five fallow generational cycles. Result showed that the mean proportions of organic matter (OM), total nitrogen (TN), cation exchange capacity (CEC) and available phosphorus (Av. P) increased substantially in the 1st and 2nd generation of fallows probably due to reduced cropping frequency. The PCA result further revealed that topsoil available phosphorus, topsoil exchangeable sodium and topsoil exchangeable potassium constituted the most significant soil properties that progressively increased across the fallow generations. As usual, nutrients in the fallow generations were confined to the topsoil. The increase in soil nutrients was attributed to the increased in tree size, vegetation cover and adequate ground cover which helped to conserve and build-up essential nutrients in the soil by minimizing the loss of nutrients through soil erosion. The study suggested that for efficient conservation practices, fallow land mostly the 1st generation fallow which was fast approaching climax should be considered for reserve. For this to be feasible, alternative means of livelihoods should be provided to reduce the wanton destruction, concentration and dependence on forest resources for sustenance.Keywords:  Fallow Genealogy, Vegetation Development, Soil, Physical Property, Chemical property, Disturbance frequenc

Variation in runoff and sediment loss in fallow and abandoned farmland in Agoi- Ekpo, Cross River State, Nigeria

A study was carried out to assess soil erosion and associated losses on abandoned cassava farmland, 3-year, 10-year and 5-year fallows in a part of the rainforest zone of southern Nigeria. The study showed that the 5- year fallow yielded the most losses as a result of its scanty herbaceous cover and existence of canopy gaps followed by the abandoned cassava farmland, while the 10-year experienced the lowest losses in runoff and sediment. Runoff loss (F = 16.089; p<0.05) and sediment loss (F = 6.355, p<0.05) varied significantly among the treatments. The study revealed erosional losses occurred in all plots and that fallows with sparse herbaceous cover were less effective in suppressing soil erosion. To reduce unproductive loss of rich topsoil, farmers were encouraged to maintain adequate herbaceous cover during cropping to speed up ecological restoration after land abandonment.Keywords: Fallow vegetation, Soil erosion, Erosional losse

The Impact of Capital Adequacy on Deposit Money Banks’ Profitability in Nigeria

The main objective of this paper is to empirically assess the impact of capital adequacy on Deposit Money Banks’ profitability in Nigeria, taking a case study of five selected banks. The empirical analysis covered the period from 1981 to 2011. The data for the study were obtained from secondary sources including the annual reports and financial statements of the selected banks and Central Bank of Nigeria (CBN) statistical bulletin. The study adopted the Engle and Granger two steps procedure in co-integration. The study revealed that capital adequacy plays an important role in explaining banks Returns On Assets (ROA) which is a measure of banks’ profitability. The positive and significant relationship between capital adequacy and banks’ profitability suggest that banks with more equity capital are perceived to have more safety and such advantage can be translated into higher profitability. The higher the capital ratio, the more profitable a bank will be. Based on the findings, It was recommended that there should be a constant review of minimum capital requirement of deposit money banks in Nigeria to the optimal level. Also Nigeria banks should be well capitalized to enable them enjoy assess to cheaper sources of funds with subsequent improvements in profit levels; this would go a long way to help the public maintain confidence in the banks and also accommodate the credit needs of customers. Keywords: Capital Adequacy, Banks’ Profitability, Return on Assets (ROA), Deposit Money Banks, Equity to Total Assets Ratio (EQTA

Influence of Vegetation Characteristics on Nutrient Loss in the Rainforest Belt of Agoi- Ekpo, Cross River State, Nigeria

The study evaluated the influence of vegetation characteristics on nutrient loss in vegetation fallows in a part of the rainforest belt in Agoi-Ekpo, Cross River State. Participatory method was used to identify fallows of 3-year and abandoned farmland. In each identified fallow category, 10 plots for vegetation estimation was established, while two runoff plots of 10m x 4m was constructed and used for nutrient loss estimation. Data was gathered during the cropping season of March to November, 2012. Results showed that on the 3-year fallow only basal cover was retained by the model and significantly explained Ca loss (R2= 0.627, F = 3.655, p<0.01), Mg loss (R2= 0.57.2, F = 3.271, p<0.05) and potassium loss (R2=0.527, F = 2.980, p<0.05). On the abandoned farmland, the model retained only crown cover and it significantly explained OC loss (R2 = 0.591, F = 3.402, p<0.01), TN (R2 = 0.599, F = 3.456, p<0.01), Ca (R2 = 0.674, F = 4.067, p<0.01), Mg (R2 = 0.796, F = 5.75, p<0.01) and K (R2 = 0.823, F = 6.090, p<0.01). The study showed that more nutrient element losses were recorded in the abandoned farmland. The study suggests that trees and shrubs should not be completely cut down on farmlands facilitate rapid vegetation restoration during land abandonment.Keywords: Nutrient loss, Vegetation characteristics, multiple regression, fallo

Assessment of Heavy Metal Status of Boreholes in Calabar South Local Government Area, Cross River State, Nigeria

Although, many heavy metals are necessary in small amounts for the normal development of the biological cycles, most of them become toxic at high concentrations. The major sources of heavy metal pollution in urban areas of Nigeria are anthropogenic, while contamination from natural sources predominates in the rural areas. The study examined heavy metal status of boreholes in Calabar South, Cross River of Nigeria. Four functional boreholes in the area were sampled. Result showed that the concentrations of iron (Fe), zinc (Zn) and Manganese (Mn) were within WHO maximum permissible limit with mean values of 0.065ml-1g, 0.015mgl-1 and 0.002mgl-1 respectively. The proportion of copper (Cu), chromium (Cr) and lead (Pb) in the sampled boreholes was zero, indicating the absence of these metals in the sampled boreholes. The absolutely low levels of heavy metal contents across the sampled boreholes showed they were not polluted and as such suitable for human consumption. The low content also revealed that boreholes in the area were located far away from dumpsites; soak away pits, automobile shops and other forms of heavy metal contaminants. In order to maintain quality status of boreholes in the area, routine monitoring and assessment of boreholes mostly the indiscriminate sinking of boreholes in the area by sanitary inspection officers was suggested.Keywords: Heavy Metal, Borehole Water, Functional Boreholes, Proportion, Quality Statu

Assessment of the Nutrient Status of Soil under Chromolaena odorata L. (Siam Weed) Fallow in Moniya, Oyo State Southwestern Nigeria

In Nigeria, soil fertility restoration for improved agricultural production is a recurrent issue of immense importance mostly with her ever increasing population currently above 150 million. Therefore, identifying sustainable ecological practice to improve soil fertility is one of the surest ways to enhance food security. The study examined the trend in soil nutrient under the canopy of Chromolaena odorata of zero, 6 months, 1 yr and 2 yr fallows. The grid system of sampling was employed to collect soil samples from ten quadrats of 5m x 5m in each of the Chromolaena fallows. Result showed that C. odorata, a plant of secondary succession had significant effect on the buildup of nutrients in the soil, as the contents of soil properties under the canopy of C. odorata progressively increased with the age of fallows, which perhaps was affected by the increase in Chromolaena plant and cover. The pH level of soils under the canopy of C. odorata especially in the 2nd year fallow considerably favoured the increase in the contents of essential elements in the soil. However, to improve soil fertility, the study suggested that C. plantshould be planted along with staple crops to help minimize nutrient loss, and also, fallows with C. plantsshould be allowed for a reasonable number of years to facilitate nutrient accretion before cultivation.Keywords: Chromolaena Density, Nutrient Status, Physical and Chemical Properties, Nutrient Accretio