Coastal Plain Sands Research Articles

Evaluating the groundwater potential of coastal aquifer using geoelectrical resistivity survey and porosity estimation: A case in Ota, SW Nigeria

Geoelectrical resistivity sounding surveys was carried out at two locations (A and B) in the new CanaanCity residential estate of Canaan land Ota, Ogun state in order to locate possible targets for groundwater explorations. A total of twelve (12) vertical electrical soundings were conducted using the Schlumberger array configuration. The interpretations of the VES curves revealed five to six geoelectrical layers at location A which comprises VES1-7. The geoelectric units consist of the topsoil, sandy clay, lateritic clay, confining bed (clayey sand), and main aquifer (sand). The top of the aquifer in this part of the study area is between 40 m and 83.5 m. Likewise, a total of five to seven layers of geoelectrical units were delineated at the location B portion of the study site (VES 8–12) similar to location A with an addition of the shale unit that was interpreted to be that of the Akimbo Formation of the Dahomey Basin. The depth to the top of the productive aquifer within location B is in the range of 40–112.4 m. The delineated basal shale layer is impermeable, serving as the base seal rock for the confined aquifer system. The estimated porosity values range from 28% to 74%, indicating that the highly porous aquifer system in the area is the coastal plain sands mixed with the alluvium sand of the Benin Formation of Dahomey Basin. The study revealed the complexity of the productive aquifer system in the area and its undulating topography.

Chemical fractionation and mobility of nickel in soils in relation to parent materials

ABSTRACT Information on the various nickel (Ni) fractions and mobility in soils in relation to parent materials is critical in understanding the contribution of parent materials to nickel bioavailability and mobilization within the ecosystem. Sixty soil samples were collected from 0 to 20, 20 to 40 and 40 to 60 cm depths of five pedons dug in each of the parent material locations (Coastal plain sands (CPS), alluvium (ALV), false-bedded sandstones (FBS) and Imo clay shale (ICS)). Distribution of Ni fractions (water soluble (WS), exchangeable (EX), specifically sorbed/carbonate bound (SSC), Iron – Manganese oxides bound (Fe – Mn), organic matter bound (OMB) and residual bound (RE) fractions) was calculated using the modified sequential extraction procedure. The mobility factor (MF) was ascertained using the metal index of mobility (IM) equation. Findings indicated that nickel fractions differed significantly (p < 0.05) with parent materials and soil depths. The SSC Ni prevailed in the soils (40.4–60.4% of total Ni), being higher in ICS soil (4.06–4.34 mg kg−1) and lower in ALV soil (3.89–4.14 mg kg−1). Organic matter bound Ni was the least Ni fraction (0–4.6% of total Ni). High Ni MF was observed (66.5–89.1%).

Influence of Seasons on Soil Properties under Oil Palm Cultivation in a Coastal Plain Sands Area of Akwa Ibom State, Nigeria

The study was to assess the Influence of Seasons on soil properties under oil palm cultivation in a coastal plain sands area of Akwa Ibom State, Nigeria. Four locations with the same parent material were identified; oil palm block of 57 years (B-57), 39 years (B-39) and 17 years (B-17) and a no oil palm block (B-0) as control. Three pits were sunk in each location and soil samples collected for both dry season and wet season. The result from the laboratory and statistical analysis showed that 32.3 %, 38.7 %, 29 % and 29 % of the soil properties were significantly (p&lt; 0.05) higher in the dry season compared to the wet season, while 6.5%, 6.5%, 12.9 % and 19.4 % of the soil properties were significantly (p&lt; 0.05) higher in the wet season than in the dry season in B-0, B-17, B-39 and B-57 respectively. Generally, particle sizes were not significantly different in the two seasons of all the blocks, whereas many of the soil chemical properties significantly changed with change in seasons. Therefore, taking the season and existing cropping system into consideration when soil quality assessment is carried out will produce a more realistic and reliable result.

Soil Microbial Activities Influenced By Oil Palm Cultivation In A Coastal Plain Sands Area Of Akwa Ibom State, Nigeria

Soil Microbial Activities Influenced By Oil Palm Cultivation In A Coastal Plain Sands Area Of Akwa Ibom State, Nigeria

Numerical classification and digital mapping of coastal plain sands of Southeastern Nigeria

The study classified the coastal plain sands of south-eastern Nigeria at the series level and modeled the classification using digital terrain attributes. The study utilized 72 secondary and 12 primary profile pits data generated from 24 and 4 locations (at 3 per location) for classification/modelling and validation respectively. The three profile pits per location represents the three topographic positions of upper, middle and lower slopes. Digital elevation model was also utilized for the generation of terrain attributes. Soil morphological characteristics were coded for suitability in statistical analysis. Hierarchical clustering was utilized in the grouping of the soil into 17 homogeneous groups referred to as soil series. Regression kriging was used to model the predicted soil series within the area covered by coastal plain sands in Akwa Ibom State. The variables that could be used in the modelling of the different classified soil series include Sand Content, aspect, flow accumulation, compound topographic index (CTI), elevation, hill shade, slope, curvature, flow direction, stream power index (SPI), profile curvature, tangential curvature (R2 = 0.21).Out of the 17 soil series classified, 14 was successfully mapped using digital technique. It was observed that 66.7% of the classified soil series were accurately predicted using digital mapping technique. The classifications carried out numerically made use of morphological discrete variables whereas digital used empirically determined continuous variables which could be more accurate. Therefore it could be inferred that the digitally produced soil classification is more accurate and 14 soil series could be identified and mapped in the study area.&#x0D; Key words: pedogenesis, digital soil mapping, soil series, hierarchical clusters, regression kriging

Interaction between sea-level changes and depositional tectonics: Implications for hydrocarbon prospectivity in the western coastal swamp depobelt, Niger Delta Basin, Nigeria

This paper presents the potential depositional framework of sandstones and unconsolidated sand reservoirs, seals, and traps in the western part of the coastal swamp depobelt of the Niger Delta Basin, Nigeria, through integration of sequence stratigraphy and seismic imaging. The integration of well logs and biostratigraphic (foraminifera and palynological) data with three-dimensional seismic volume established the sequence stratigraphic framework, which has improved our understanding of the impact of sea-level changes in the distribution of sand facies. Four third-order seismic depositional sequences (sequences 1–4) of Serravallian deposits were identified based on the Vail stratigraphic concept. Depositional processes, structures, thickness, and seismic signatures vary in each sequence. Sequence 1, dominated by mud and very fine-grained sand facies, represents the outer shelf–shelf margin setting and has experienced shale tectonics (ductile deformation). Sequences 2 and 3 consist of alternating sand–shale facies and have experienced gravitational tectonics. Although sequence 2 represents middle shelf–inner shelf setting, sequence 3 represents inner shelf–transitional setting. Sequence 4 consists of thick fluvial–coastal plain sand facies and represents deltaic plain or continental sediments. These deposits reflect postgravitational tectonics. Within the third-order sequences are fourth-order sequences that recorded the interaction between small-scale transgressive–regressive cycles and depositional tectonics. The potential reservoirs within these sequences are stacked channel sandstones, shoreface sandstones, and heteroliths. The juxtaposition of the potential reservoirs against transgressive shales provides potential seals and traps. Structural interpretation shows synthetic and antithetic faults. In addition, event maps at various ages document structural closures that indicate the existence of possible hydrocarbon leads and prospects.

Polyacrylamide and Chitosan Biopolymer for Flocculation and Turbidity Reduction in Soil Suspensions

Recent studies have shown that turbidity in construction site runoff can be greatly reduced by chemical turbidity control. This study evaluated the performance of chitosan-based biopolymer (dual polymer system, DPS) vs. anionic polyacrylamide (PAM) for turbidity reduction and characteristics of flocculated sediments using two soils from North Carolina, USA. The soils were Coastal Plain sand (CPS) and Piedmont Sandy loam (PSL), representing smectitic and kaolinitic mineralogy, respectively. A series of jar tests for DPS (charging agent + chitosan) and two commercial PAM products were conducted to find optimal concentration for turbidity reduction in the respective soil suspension (20 g L−1 in soil loading). After determining the optimal flocculant concentrations, the soil suspensions treated with DPS, PAM, and no flocculant (control) were investigated for turbidity change over settling time, floc stability, floc growth, settleable solids through Imhoff cone test, and particle size distribution by a laser diffraction method. Both flocculants were effective in reducing turbidity (> 90%) in PSL suspensions while PAM outperformed DPS in CPS suspension. Settleable solids volumes increased with flocculant treatments by 23–41% relative to untreated soil suspensions (13 mL for CPS and 20 mL for PSL), indicating efficacy of flocculant-assisted particle settlings. PAM-treated particle size was greater (115 µm, median diameter) than DPS (84 µm) in PSL suspension, both being 3–5 times greater than untreated suspension (24 µm). Repeated stirring resulted in floc growth with PAM but not with DPS. Our results suggested that practitioners using flocculants to treat turbid water in construction site need to perform tests with different flocculants to determine the optimal treatment on their project. While PAM has advantage over DPS as a single flocculant treatment, DPS could be an alternative due to its eco-friendly features.

Effect of simulated acid rain on growth and micronutrient uptake of okra (Abelmoschus esculentus) on coastal plain sands in Abia State, South-eastern, Nigeria

The study was conducted in April, 2019 at Umudike to examine the impact of simulated acid rain (SAR) and frequency of SAR spray on growth and micronutrients content of okra (Abelmoschus esculentus (L.) Moench) in an ultisol at Umudike. The treatments consisted of three (3) pH levels: Coca-cola solution (pH 2.7) and SAR (pH 3.5 and 5.5) as well as control (water) and; three (3) frequency of foliar spray at 1, 2 and 3 day weekly, arranged according to their respective pH values and spray treatments in a completely randomized design (CRD) replicated three times. Plant leaves were analysis for micronutrients (Cu, Fe, Mn and Zn) content. The result shows that, under the stress of SAR and frequency of SAR application, growth parameters measured; leaf number, shoot height and leaf area were significantly reduced, compared to the control treatment. Nutritional analysis of the leaves also revealed that, the content micronutrients in okra, increased with declining pH value of AR and frequency of application, from pH 5.5 to pH 2.7. Coke solution (pH 2.7) and three (3) days per weekly application of SAR gave the highest reduction in plant growth parameter in Okra but, had higher increased in micronutrients content, respectively. Further result showed that okra (Abelmoschus esculentus (L.) Moench) is resistant to SAR from pH ≥5.5 in terms of growth and nutritional values.

Mapping Ground Water Potential Recharge Zones in Parts of Akwa Ibom State Using Geographic Information System (G.I.S)

The study was conducted to map ground water potential recharge zones based on physical parameters in southern parts of Akwa Ibom State using Geographical information system (GIS). The aim was to produce ground water recharge potential map for the protection of water quality and the management of ground water systems. Thematic maps of lithology, land cover/ land use, lineaments, drainage, and slope of the study area were produced from various sources. The influence of each factors to groundwater recharge and interaction between the factors were examined and ranks were assigned. Weighting values were assigned according to the degree of the Multiple Influencing Factors (MIF). All the thematic maps or layers were integrated applying weighted overlay analysis in a GIS environment (Arc Map 10.5 software) to produce the resultant map. The study produced a ground water recharge potential map of parts of Akwa Ibom State. The resultant map indicated that the most effective groundwater recharge potential zone was trending in the NW – SE direction. In this region, the coastal plain sands of the Benin Formation, the agricultural land and forest possesses high infiltration ability. Additionally, the concentration of drainage also indicates the ability of stream-flow to recharge the groundwater system. The downstream region is least effective for groundwater recharge, mainly due to its elevation being as low as sea level. Keywords: Mapping, Groundwater, GIS, Lineament, Drainage, Recharge DOI: 10.7176/CER/12-2-08 Publication date: February 29 th 2020

Assessment of Corrosion of Mild Steel Buried In Soils of the Niger Delta, Nigeria

This study determines the corrosion rate and percent weight loss of mild steel buried in soils of the Niger Delta Area of Nigeria. Six geologic zones representing the upland and wetland soils were used for the assessment. The corrosion rates of mild steel in these soils were monitored to assess the extent of corrosion. However, the upland soils (Odagwa, Ogoni, Ahoada and Omoku) were more resistant to corrosion than the wetland (Kaiama and Elebele) soils. The corrosion rate of mild steel at the 24th month was in the following order of corrosivity: Elebele &gt; Kaiama &gt; Omoku &gt; Ahoada &gt; Ogoni &gt; Odagwa. The percent weight loss was higher at the 24th month, with the highest values found at the Meander Belt Deposits of Elebele. Alternately, the Coastal Plain Sands were found to have the least percent weight loss with the lowest value recorded at Odagwa site at the 24th month. The percent weight loss at the 24th month is in the following order: Elebele &gt; Omoku &gt; Kaiama &gt; Ahoada &gt; Ogoni &gt; Odagwa. The variation in corrosion rate and weight loss of mild steel buried in the different soil types is caused by the aquic moisture regime of the soils, anthropogenic activities carried out, microorganisms present in the soils, and also, the physico-chemical properties of the soils.

Soil Carbon Sequestrations in Forest Soils in Relation to Parent Material and Soil Depth in South-Eastern Nigeria

There has been increased interest in soil organic carbon in recent times because of its role in carbon sequestration. Different parent materials affect soil properties and hence will influence how much carbon is sequestered by soil. The study was conducted in June 2019 to investigate soil carbon stock in forest soils with respect to their parent materials in three States in South-eastern Nigeria. Sampling was aided by the location map of the area and free soil survey method was used to locate sampling points. 0ne profile was dug in each location and described using the Food and Agricultural Organization guideline. A total of twelve soil samples were collected and analyzed for selected properties. Results showed that sand content was significantly higher in soils under coastal plain sands (851.96 g·kg−1) and was lowest in soils of Imo clay shale (605.60 g·kg−1). Clay content was higher in soils of Imo clay shale (277.34 g·kg−1) and was lowest in coastal plain sand (118.80 g·kg−1). Silt and clay had moderate variation in coastal plain sand (>15 ≤ 35%) and high variations in Asu River and Imo clay shale (CV > 35%). The soils studied were generally acidic with values ranging (3.52) in soils formed from coastal plain sand, followed by forest soils of Imo clay shale (3.64) and Asu river group (3.85). Soil organic carbon decreased with increase in soil depth in all soil parent materials studied. Mean values ranged from 6.14 g·kg−1 in soil underlain by coastal plain sand to 10.62 g·kg−1) in soils of Imo clay shale. Soil carbon sequestered under the three different parent materials ranged from 1575 - 4676.41 (g·cm−2). Also, soil depth had a notable impact on carbon sequestration with values ranging from 1529.42 - 4374.0541 (g·cm−2) and the thicker the horizon, the more carbon sequestered. Hence, the study concluded that more carbon is sequestered in the subsurface horizons of the soil pedons than in the epipedons.

Modelling soil properties from horizon depth functions and terrain attributes: An example with cation exchange capacity

The objective of this study was to, through the distribution of some soil properties, model cation exchange capacity (CEC) in soils formed on gently undulating coastal plain sands of southeastern Nigeria using genetic horizon functions and terrain attributes. A total of 19 profile pits were prepared, described and 104 genetic horizons were identified and sampled, processed and analysed in the laboratory. Data were generated on the soil characteristics, including particle size fractions, hydraulic conductivity, bulk density, organic carbon, pH and electrical conductivity. Terrain attributes that were generated from digital elevation model include aspect, compound topographic index (CTI), Flow direction, curvatures, slope and stream power index (SPI). Data generated were analysed using descriptive statistics, correlation and regression. The terrain attributes were modified with genetic horizon depths, bulk density and clay content for the modelling process. Sand content, bulk density and cation exchange capacity possess geogenic rather than pedogenic characteristics and were normally distributed. The indication is that the two groups of terrain attributes depended on the mass per unit area of soil and clay content in their influence on these ultisol profiles. Paired comparison, root mean square error and normalized root mean square error indicated that the model was a good fit and could be useful in the prediction of soil properties and management of coastal plain sands.

Local Geology, Shear Strength Properties and Bearing Capacity of Coastal Plain Sands in Uyo Metropolis, Akwa-Ibom State, Southeastern Nigeria

The Bearing capacity of the soil within Uyo metropolis in South-Eastern State of Akwa Ibom was investigated in this study. The soil belongs to Coastal Plain Sand often called the Benin Formation in the geology of Niger Delta. Both Field and Laboratory methods were employed in the study. The field method consisted of Cone Penetration Test (CPT) with a 2.5 ton Dutch Guada cone penetrometer, and the Light weight penetrometer LRS 10. For the CPT, depth of investigation was refusal depth which varies from about 9.0 m to 20.0 m. The depth of investigation by the LRS 10 was not more than 6.0 m. The direct parameter the LRS 10 evaluates is the relative density. Soil sounding with the LRS 10 indicated for all the sites a ‘loose to medium’ consistency. No dense or very dense stratum was encountered. The Laboratory method employed was the Direct shear box tests This was used to determine the cohesive property and angle of shearing resistance of the soil, that is the C- ∅ property. The cohesion varies very widely; with a value ranging from a zero value to 54 kN/m2. The angle of shearing resistance ranges from 8º to 30.7º, with more than ninety percent falling below 28º, indicating a highly compressible soil that is prone to local shear failure. Ultimate bearing capacities are as low as 100.93 kN/m2 and as high as 571.1 kN/m2. Settlement associated with safe bearing pressure estimated from CPT data ranged from 0.35 cm to 3.89 cm. while that from laboratory gives lesser values, thereby making that from the field value conservative.

COMPARATIVE ASSESSMENT OF SOME PHYSICAL PROPERTIES AND ORGANIC MATTER CONTENT OF SOILS DERIVED FROM DIFFERENT PARENT MATERIALS IN AKWA IBOM STATE, NIGERIA

The study of soils derived from different parent materials is useful in formulating appropriate management schemes for soil health and agricultural production. A comparative assessment of some physical properties and organic matter content of soils formed from coastal plain sands (CPS), sandstone (SST) and river alluvium (ALV) was conducted in Akwa Ibom State, Nigeria. Topsoil samples (0 – 30 cm) were collected from ten points in soils of each of the three parent materials for laboratory analyses. The soil samples were analyzed for texture, macro and micro aggregate stability indices, soil water characteristics, bulk density and organic matter. Data generated were subjected to Analysis of Variance to compare properties of soils of the different parent materials. Significantly different means were separated using the Least Significant Difference at 5% probability level. Results showed that soils of SST and CPS parent materials both had loamy sand texture while that of ALV soil was clay. Bulk density of ALV soil (1.20 Mg m-3) was significantly lower (p≤0.05) than those of CPS (1.55 Mg m-3) and SST (1.39 Mg m-3). Significantly higher (p≤0.05) mean weight diameter (MWD) (2.01 mm), aggregated silt+clay (51.96%) and clay flocculation index (89.00%) were observed in ALV soils than in CPS and SST soils while the dispersion ratio and clay dispersion index were significantly higher (p≤0.05) in CPS and SST soils than in the ALV soil. Alluvial soil had significantly higher (p≤0.05) saturation water content (SWC), field capacity (FC), permanent wilting point (PWP) and available water content (AWC) of 0.61, 0.45, 0.25 and 0.20 m3 m-3, respectively, than those of CPS and SST. Alluvial soil also had the lowest cumulative infiltration (3.05 cm) and saturated hydraulic conductivity (0.40 cm hr-1) relative to those of CPS and SST. The CPS soil had significantly lower (p≤0.05) organic matter content (2.07%) than SST (3.06%) and ALV (3.34%) soils. Cumulative infiltration (I) significantly and positively correlated with total sand (TS) (r = 0.710*) in the CPS soil, and Ksat (r = 0.681*), MWD (r = 0.829**) and CFI (r = 0.655*) in the SST soil. In the ALV soil, cumulative infiltration positively correlated with total porosity (r = 0.770**) and negatively with bulk density (r = - 0.770**). Saturated hydraulic conductivity (Ksat) had a positive correlation with SWC (r = 0.745*) and TP (r = 0.833**), but a significant and negative correlation with BD (r = - 0.833**) in SST soil. Field capacity (FC) positively and significantly correlated with TP (r = 0.638*) in CPS soil, and with MWD (r = 0.713*), CFI (r = 0.647*) and OM (r = 0.651*) in SST soil and with TP (r = 0.790**) and OM (r = 0.672*) in ALV soil. The correlations of FC with BD (r = - 0.638*) in CPS soil, with CDI (r = -0.647*) in SST soil and with BD (r = -0.790**) in ALV soil were significant and negative. MWD positively and significantly correlated with organic matter (r = 0.699*). The clayey ALV soil will be suitable for paddy rice production and dry season crops due to its higher water retention capacity than the CPS and SST soils which will be better utilized for vegetable crop production under irrigation. The CPS and SST soils can also be applied to intensive crop production under rain fed condition and supplemented with irrigation.&#x0D;

Extracting some soil parameters and estimating elastic settlements from Direct shear box data for a granular C- Ø soil

Direct shear box tests were carried out on some soil samples obtained from some locations around Uyo metropolis in Akwa-Ibom State, Southeastern Nigeria. The dominant geology is the Coastal Plain Sands. From the test results, the C-O properties of the soils were determined. These values were used to compute ultimate and allowable bearing capacities for the soil samples. Elastic, and shear modulus parameters were computed for the different shear values readings for each vertical loading scheme. Poisson ratio was also computed for the same loading scheme applying the elastic relationship between shear modulus and elastic modulus. These parameters were used to compute elastic settlement using the classical elastic theory equation. Two other modified equations of the elastic theory equation and a consolidation equation was also used to compute immediate and consolidation settlements respectively. The values of immediate settlement obtained for the classical elastic equation is less than those computed by the other two modified equations. This is attributed to the fact that the other two equations assumed a constant value of Poisson ratio for the different imposed loads for which computations were made. For the allowable load of 138.54 kPa the classical elastic theory gave an immediate settlement value of 1.02 cm; the other two modified forms of the theory gave values of 2.94 cm and 4.0 cm. Elastic modulus and Poisson ratio obtained from the Direct shear test for the load are 5662.86 kPa and 0.49. These values were used in the elastic equation. The same value of 5662.86 kPa was used in the other two modified elastic formulas, but Poisson ratio values of 0.15 and 0.2 were assumed for all loads. Direct shear box test provides a convenient, but plausible means of determining parameters required to compute immediate settlement for the type of soil investigated.

Season-induced variation in water table depth and selected chemical parameters of groundwater in Lagos Coastal Plain Sand Aquifer, Nigeria

In-situ measurement of depth to aquifer and water table was undertaken in 45 protected dug wells over two seasons. Samples were also analyzed for pH, EC, TDS, Ca, Cl, K, HCO 3 , CO 3 , SO 4 , Mg, K, and Na using universally accepted laboratory techniques. The study was aimed at examining seasonal variations in the chemistry of groundwater in the Lagos Coastal Plain Sand aquifer and its potability using the WHO standards. The study area covered parts of the Lagos Metropolis and the entire settlements of Ikorodu, Epe, and Badagry. The sample locations were mapped with ArcMap 9.3 software while the data were analyzed using descriptive statistics, paired sample T-test, correlation and multivariate statistical techniques using SPSS software 17.0 version. The result shows that about 60% of the samples had pH below the WHO minimum standard of 6.5 in both the dry and wet seasons. Mean EC and TDS levels were excessively high at Igando in both seasons. Some major ions, calcium, magnesium, potassium and sodium, and chloride exceeded the WHO limit at Oko-Oba, Ilogbo, Shomolu and Shogunle in the dry season. They were also excessively high in the wet season at Igando, Oko-Oba, Odo-Onosa, Ilogbo, Shomolu, and Shogunle. Correlation analysis shows that a significant relationship exists between the parameters at p<0.05 with the exception of Mg 2+ and K + in both seasons. The result of the paired sample T-test also shows significant variations among pH, Ca 2+ , HCO 3 - and Mg 2+ with higher mean values in the dry than the wet season except for pH. Factor analysis identified salinity and anthropogenic activities as the two major sources of pollution. These account for about 74.48% and 84.21% of the total variances in dry and wet seasons, respectively. Consequently, protection of the recharge areas of the aquifer from environmental pollution and formulation and enforcement of appropriate policies that will stem the rate of indiscriminate groundwater exploitation and prevention of saline water intrusion in the coastal settlements are recommended. Keywords: Aquifer; Coastal Plain Sand; Groundwater; Lagos; Seasonal variations, Water quality parameters

Integration of aeromagnetic and electrical resistivity imaging for groundwater potential assessments of coastal plain sands area of Ado-Odo/Ota in southwest Nigeria

This study aims to investigate the groundwater potential of Coastal Plain Sands area of Ado-Odo/Ota within Dahomey Basin using the integration of aeromagnetic method and electrical resistivity imaging. The aeromagnetic method is applied to reveal the possible hydrogeological structures (such as lineament or fracture) buried in the subsurface. The lineaments which are interconnected are observed in the eastern part of the study area while the western part is void of the interconnectivity of lineaments. Resistivity technique is applied in regions where there are interconnectivity and non-interconnectivity of lineament to delineate occurrence of groundwater about the observed lineament. The depths to magnetic sources range between 102.6 and 1965.2 m. Furthermore, the result of resistivity technique shows that the depth to aquifer ranges from 40 to 100 m with corresponding resistivity values that range between 150.0 and 350.0 Ωm in the region of the interconnectivity of lineament, which is the eastern part of the study area (Igboloye-Covenant University area) and had high groundwater potential. The western part which is void of the interconnectivity of lineaments (Alapoti area) ranges from 80 to 130 m with resistivity values that range between 250.0 and 450.0 Ωm suggesting that the area has low groundwater potential. The study, therefore, shows that the occurrence of groundwater in Ado-Odo/Ota community is a function of hydrogeological structures such as lineaments or fractures, and as a result, this information could serve as guide for borehole drillers, civil engineers and resident of the study area for proper planning before siting borehole either for domestic or industrial use.

Evaluation of Infiltration Characteristics of Soils Developed on Coastal Plain Sands in Calabar Municipality Local Government Area, Cross River State, Nigeria

Infiltration of water into the soil is an important physical process affecting the fate of water under field conditions, especially the amount of subsurface recharge and surface runoff and hence the hazard of soil erosion. The study was conducted to evaluate the infiltration models of soils developed on coastal plain sands and to select a suitable models as a basis to improve the management of the soil. A total of 16 infiltration runs were made with the double ring infiltrometer. For the purpose of getting best fitting model, the results obtained from various infiltration models were compared with observed field data. The parameters considered for best fitting of model were correlation coefficient and coefficient of variability (CV). Model-predicted cumulative infiltration consistently deviated from field-measured data, that is, the models under-predicted cumulative infiltration by several orders of magnitude for Kostiakov, Green Ampt and Philip model but the model over predicted cumulative infiltration for Horton model. The results of the soil samples analysed revealed that the mean values of 707.50, 208.13 and 84.38 gkg-1 for sand, silt and clay with the textural class of sandy loam. The bulk density, particle density and total porosity had mean values of 1.84 gcm-3, 2.44 gcm-3 and 22.56%. However, there was a fairly good agreement between mean-measured cumulative infiltration (7.30 cm/hr, CV = 32.19%); Philips (1.93 cm/hr, CV = 42.49%); Kostiakov (0.13 cm/hr, CV = 30.77%); Horton (64.49 cm/hr, CV = 22.39%) and Green Ampt model (42.04 cm/hr, CV = 0.57%) respectively. The data however showed that the correlation coefficient for Kostiakov (1.00) was best fitting in predicting the field measured data and this was closely followed by Green Ampt (0.88); while Philip’s model and Horton model showed a negative correlation (r = -0.88 and r = -0.82) with the field measured data. Conservation measures involving mulching, cover cropping and afforestation are recommended to improve the soil structure and infiltration capacity.

Distribution of Primary Nutrients (NPK) to Crop Production in Profiles of Soils Derived from Coastal Plain Sand in Ikot Ekpo, Calabar, Cross River State, Nigeria

This study was conducted to evaluate the distribution of primary nutrients (NPK) in profiles of the coastal plain soils of Ikot Ekpo, Calabar, as well as evaluate other soil properties critical to agricultural productivity, in a bid to generate data that will serve as a guide to effective land use and management of the soils for arable crop production. Three (3) Profile pits were dug on the crest, middle slope and valley bottom, and soil samples were collected from their pedogenetic horizons for analysis. Analytical results showed the three profiles of coastal plain soils studied had predominantly sandy particle sizes (ranged from 770 - 910 gkg-1 sand across the three profiles) and mostly loamy sand in texture; especially at the topsoil level. The soils were also acidic (pH 4.7 to 5.1) and low in organic matter (1.0 mg kg-1 to 16.0 mg kg-1) as expected. Generally, the soils were found to be low in total nitrogen content (0.1 to 1.3 mg kg-1) and exchangeable potassium (0.08 to 0.10 cmolc kg-1); however, they were high in available phosphorus (17.20 to 29.75 mg kg-1). NPK distribution charts showed that N and P decreased consecutively with increasing depth for the crest profile. The middle-slope and valley bottom profile showed no definite pattern of distribution. However, the concentration of NPK was highest at topsoil level across most profiles. N had the shallowest intra-profile distribution with significantly higher levels of topsoil concentration indicated by the high percentages of intra-profile CV (94%, 85% &amp; 97% for CUF, MUF &amp; VUF respectively). P showed a shallow intra-profile distribution across the three profiles but did not vary significantly from the intra-profile mean (12.5%, 12.0% &amp; 2.6% for CUF, MUF &amp; VUF respectively). On the other hand K was more evenly distributed within all three profiles ( CV of 9.4%, 5.3% &amp; 8.6% for CUF, MUF &amp; VUF respective) compared to N and P. Inter-profile distribution of NPK showed that N and P had higher concentrations at crest level, with P showing consecutive decrease in concentration down the slope. This study therefore recommends adoption of different NPK fertilizer recommendations for different soil depths and topographic locations for optimal productivity.

Effect of Zinc Application Rates on Manihot esculenta Yield Grown in Coastal Plain Sand Soils of Nigeria

Effect of Zinc Application Rates on Manihot esculenta Yield Grown in Coastal Plain Sand Soils of Nigeria