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Articles by E.U. Onweremadu
Total Records ( 17 ) for E.U. Onweremadu
  E.U. Onweremadu , A.C. Udebuani and P.N. Abara
  The researchers studied soil carbon accumulation and soil microbial biomass under forest and arable land use types in soils of dissimilar lithology origin in Southeastern Nigeria. Soil samples were randomly collected from each land use type among the soil groups. Soil cores were collected for bulk density determination while moist soil samples were used for the estimation of soil microbial biomass. Standard techniques were used in the laboratory analysis of selected parameters. Soil data were statistically analyzed using standard deviation, coeffient of variation and one way Analysis of Variance (ANOVA). Least significant difference at 5% probability was used to identify significance among means. Means values of Soil Organic Carbon (SOC) were highest in soils under forest land use. About 59.3-70.2 ton ha-1 bit when compared with values from arable land use (39.3-46.8 ton ha-1). Stock of soil differed among parent materials. There were significant (p≤0.05) differences in Soil Microbial Biomass Carbon (SMBC) and Soil Microbial Biomass Nitrogen (SMBC) among land use types and soil groups.
  E.U. Onweremadu , F.O.R. Akamigbo , C. A Igwe , E.C. Matthews-Njoku and P.C. Obasi
  This study was designed to identify obstacles to the adoption of soil survey information in Abia and Imo States of Southeastern Nigeria. A structured interview schedule was used in obtaining information from 450 respondents. Data were analysed using percentages, multiple regression and factor analysis. Results showed that age (t = 2.21), education (t = 2.00) and years of farming experience (t = 2.06) were significant in influencing the adoption of soil survey information. The major factors affecting adoption of soil survey information were management and economic and technical and structural.
  E.U. Onweremadu , C.C. Asiabaka , C.P. Anyanwu , G.A. Anyanwu , E.B. Etuk and B.O. Esonu
  This study evaluated animal manure production, management techniques, utilization and effect on soil productivity in Amuzu Mbaise, Southeastern Nigeria. The study, which was conducted in 2006 used structured interview schedule at a phase of the study. In another phase, we studied the effects of animal manures from muturu (Local cattle), goats, sheep and pigs on a degraded Isohyperthermic Kandiudult using maize (Zea mays L.) as a test crop. The potted experiment was set up in a greenhouse using a Completely Randomized Design (CRD), with each treatment replicated 9 times. Five treatments used included manures from Muturu, goats, sheep, pigs and control. Relevant measures of central tendency and dispersion were used in the statistical analysis of socio-economic and agronomic data. Results showed that a greater number of households engaged in goats and sheep, thereby making their manures relatively more abundant than other livestock. Majority of the livestock fend for of themselves in rangelands with pigs being more confined. Animal manures were collected and used although they were inadequate and bulky while there was poor knowledge of urine as biofertilizer quality of manures differed with handing technique and manure improved maize (Zea mays L.) performance significantly (p = 0. 05). Soil chemical fertility was significantly (p = 0.05) improved. Integrated studies especially is if affects indigenous knowledge will be helpful.
  E.U. Onweremadu , E.T. Eshett , U.E. Ogundu , C.P. Anyanwu and J.C. Obiefuna
  The study investigated influence of some soil properties on sorption and bioaccessibility of cationic chromium [Cr (III)] of rangeland soils proximal to military settlement at Obinze, Southeastern Nigeria in 2006. Field sampling was guided by a transect drawn from an open dump site away towards River Otamiri, Owerri, Southeastern Nigeria. Three land units, namely A, B and C from which soil samples were collected and analyzed using routine and special techniques. Soil and plant data were subjected to analysis of variance (ANOVA) of the Mix-model of SAS computer software and multiple regression analysis for purpose of modelling. Results showed that Cr sorption and biaccessibility varied among land units with the entire site having high potentials of bioavailability and biotoxicity. It was also found that clay-content, cation exchange capacity, soil pH and total inorganic carbon are good predictors of Cr (III) bioaccessibility in studied soil.
  E.U. Onweremadu , C.C. Opara , U. Nkwopara , C.I. Duruigbo and I.I. Ibeawuchi
  Vital 5 variety of cowpea was cultivated on a very sandy ultisol of Owerri, Southeastern Nigeria-using 3 rates of ground seashells, namely 0 t ha-1, 1 t ha-1 and 2 t ha-1. Results showed that soil pH increased from 3.3 (0 t ha-1), 4.2 (1 t ha-1 ground seashells) to 4.3 (2 t ha-1 ground seashells) Aluminum saturation (ALSAT) decreased from 64% (0 t ha-1), 46% 1 t ha-1) to 38% (2 t ha-1) while base saturation (BSAT) increased from 18% (0 t ha-1), 41% (1 t ha-1) to 52% (2 t ha-1). Available phosphorus distribution was 6.8, 24 and 32 ppm for 0, 1 and 2 t ha-1, respectively. Yield responses varied according to rate of lime (ground seashells) application with 1, 302.0, 1808.0 and 1896.5 kg ha-1 for 0, 1 and 2 t ha-1, respectively.
  E.U. Onweremadu
  This study investigated the use of Isotope Exchange Kinetics (IEK) technique to estimate lability and temporal variability of cadmium (Cd) in arable soils proximal to an automobile service centre at Owerri, south-eastern Nigeria. Thirty topsoil samples (0-10 cm depth) were collected from 5 arable farms receiving waste materials from automobile servicing. The samples were subjected to experimental conditions to determine exchangeable Cd using the IEK technique. There were slight to moderate variation in the distribution of soil exchangeable Cd among farms. Results also showed that isotopically exchangeable Cd (E(t)) predicted exchangeability of Cd up to 24 h of exchange from a short-term isotopic kinetics, that is, at >60 min. There was significant positive relationship r(I)/R (ratio of the radioactivity remaining in solution after 1 min of exchangeable to the total introduced radioactivity R) and exchangeable Cd (r = 0.8**; p<0.01). Interestingly, there was no significant relationship between soil pH and kinetic parameters.
  E.U. Onweremadu and K.D. Peter
  We investigated pedogenic processes taking place in two microclimates in Owerri area, Southeastern Nigeria. Target sampling technique was used and a soil profile was sunk in each microclimate, namely mixed vegetation and pineforest. Each profile was dug and described according FAO procedure. Some soil properties were studied in the field and laboratory using routine analytical tools. Soil temperature and moisture were studied for 5 years and mean values were reported. Results showed dominance of littering, melanization, eluviation, illuviation, leaching and decomposition processes in the studied pedons although the rate varied among mixed vegetation and pineforest. Stronger and darker peds were recorded on soils developed under mixed vegetation. Soils were sandy in both vegetations. Clay bulge was distinct in soils developed under mixed forest and ranged from 90-150 g kg–1 unlike soils of the pine forest (50-120 g kg–1). Soils under mixed vegetation were more porous (37-52%) compared with 31-47% recorded in soils under pine forest. High values of organic carbon (20 g kg–1) was found in epipedons of soils under mixed vegetation compared with 11.0 g kg–1 obtained in soils of the pine forest. Base saturation, effective caution exchange capacity and calcium-magnesium ratio values were higher in soils under mixed vegetation. Soil temperature values were higher in pine forest ranging from 14.3-14.9% while the reverse was the case in soil moisture when compared values reported in mixed vegetation.
  E.U. Onweremadu , F.O.R. Akamigbo and C.A. Igwe
  This study investigated the relationship between volume shrinkage properties of soils derived from different parent materials in Central Southeastern Nigeria as they related to selected soil physical properties. Using a free survey technique and guided by a geological map of the area, field sampling was conducted in the early months of 2005. Routine analyses were done using collected soil samples. Results showed significant (p<0.05) variation in sand, clay, waterholding capacity, Atterberg limits and Co-efficient of Linear Extensibility (COLE) among the 6 studied soil groups. Volume shrinkage results indicated severe shrinkage (20-30%) rating for soils derived from Shale, moderate shrinkage (10-20%) for soils formed over Lower Coal Measures and Falsebedded Sandstones and slight shrinkage (0-10%) ratings for the rest. The COLE, used as an index of VS correlated significantly (p<0.05; n = 150) with waterholding capacity (WHC), Liquid Limit (LL), Plastic Limit (PL), Plasticity Index (PI) and clay content. A model was generated which expressed good predictive relationship between COLE and selected physical properties (R = 0.87; R2 = 0.75; 1-R2 = 0.25, RMSE = 0.01 and Bias = +0.00001), indicating high accuracy and little over-estimation by the model. More soil and soil related variables may further improve generated model (s), thus should be included in future studies.
  E.U. Onweremadu
  This study investigated the properties of an ultisol amended with Cassava Peel (CP), Cattle Dung (CD) and Poultry Droppings (PD). The potted experiment was set-up in a greenhouse using a Completely Randomized Design (CRD). Maize (Zea mays var. Western Yellow) was used as a test crop. Pre-planting soil characterization showed degradation but some properties were reversed by using CP, CD and PD in two cropping seasons (2004 and 2005). Highest grain yield of 4.84 g pot1 was recorded. A combination of CP and PD yielded 5.57 g pot1 grains. There were significant moisture correlations between performance parameters of maize and soil properties in all the amendments (p< 0.05). Post-planting study showed that CD-amended soils had a mean total nitrogen value of 4.90 g kg1 while PD improved soil phosphorus and potassium by having 176.67 and 24.30 g kg1, respectively. Soil amendments increased soil pH while soils from control pots showed a reduced pH from 4.10 (0.1 N KCl) to 3.90 (0.1 N KCl) after second cropping.
  E.U. Onweremadu
  This study evaluated temporal soil calcium loss within the soil and uptake by plants using Gmelina arborea form 2002 to 2006 at a watershed in Owerri, Southeastern Nigeria Forty pedons were dug and sampled at a regular grid of 400x400 m while 10 Gmelina plants were marked and used for the temporal evaluation of calcium (Ca). Standard analyses were performed on both soil and plant samples. Data obtained were subjected to analysis of variance (ANOVA) and correlation analyses using standard computer software. Results showed significant (p<=0.05) differences in elemental ratios with depth and time. Leaf Ca also varied significantly (p = 0.05) temporally. There were significant positive correlations between soil and plant Ca in 2002 and 2003, non-significance in 2003 while significant negative correlations (p<0.0001) in 2005 and 2006.
  E.U. Onweremadu , E.T. Eshett , M.C. Ofoh , M.I. Nwufo and J.C. Obiefuna
  We investigated the effects of Bulk Density (BD) and moisture content θv on seedling performance on a Typic Topaquept at Iyienyi Ibeku, Abia State, Southeastern Nigeria in 2005/2006 study session. A transect technique aided field soil sampling at identified physiographic units of Crest, Midslope and Footslope. A 7x7 factorial greenhouse experiment was conducted to create a matrix of BD and θv which enabled better understanding of compaction effects on seedling growth of Citrus sinensis Var Etinan. Data were subjected to statistical analysis using SAS computer software. Results showed that BD and soil strength decreased with mean root length density. Again, BD had significant (p< 0.0001) negative correlations with root performance. Moisture content had a significant positive correlation with root performance (R = 0.72; p< 0.0001). Soil moisture and BD were good predictors of root length density (R2 = 0.79) with high degree of accuracy (RMSE = 0.07) and slight over-estimation (Bias = + 0.0001): Mean root length density increased downslope and this was the trend in shoot yield. Fairly high values of coefficient of alienation, suggest the inclusion of other relevant variables in future modelling.
  G.O. Ihejirika , M.I. Nwufo , C.I. Durugbo , I.I. Ibeawuchi , V.H. Onyia , E.U. Onweremadu and P.N. Chikere
  Storage studies of groundnut (Arachis hypogeae L) in South B Eastern Nigeria were conducted to find out the rate of rot disease and the fungi responsible for the disease. Twenty-five storage locations were investigated. They were seriously infected with rot disease. On isolation on Potalo Dextrose Agar, the injected material yielded three different fungi all of which were Aspergillus flavus link. 60% of the fungi were Aspergillus niger Van Tiegh, 25% Aspergillus versicolor (Vuill) Tirab. While Aspergillus fresen was 15%. The Aspergillus niger Van Tiegh was 5-6 cm with brownish colour at center and whitish at edge. A. versicolor (Vuill) Tirah was 4-5 cm still with brownish colour but shades of white at edge while A. fresen was 3.5-4 cm with light brown at center and whitish at edges.
  E.U. Onweremadu
  This study investigated Phosphorus (P) sorption characteristics of 60 soil samples formed over 6 different parent materials in south-eastern Nigeria relating that to some soil properties. Soils were analyzed for pH, clay, Bulk Density (BD), Organic Carbon (OC), Mehlich-3 extractable calcium (CaM3) ammonium oxalate and Mehlich-3 extractable P, aluminium (Al) and iron (Fe). The oxalate and Mehlich-3 extractable elements were used in estimating Phosphorus Saturation Index (PSI). There were significant relationships between P saturation indices and soil attributes in the study site at p&le0.01 and p&le0.05. However, these correlations were least in shale-derived soils due to high content of CaM3. A P-sorption capacity model resulted from a multiple regression analysis using soil attributes as independent variables. The model showed high predictive ability (r2 = 0.77; RMSE = 3.70) with little underestimation (bias = -0.09).
  E.U. Onweremadu
  Near gully sites in southeastern Nigeria were investigated from April to July 2005 to ascertain their erodibility potentials. Soils were sandy and of low Silt-Clay Ratio (SCR) but were eroding. Exchangeable Sodium Percentage (ESP), carbon content, silt, clay and Calcium-Magnesium Ratio (CMR) tended to influence erodibility of these soils. They correlated significantly with Dispersion Ratio (DR) (p≤0.05). Exchangeable sodium percentage was higher in pedons near gully sites (ESP = 1.4-5.1) compared with results of non-gully site (ESP = 0.1-0.3). Calcium-magnesium ratio (CMR) was generally narrow (0.3-3.0). Organic matter content was very low in pedons near gully sites (less than 11%). Cation exchange capacity was lower in sites affected by gullying (CEC = 3.50-7.00 cmol kg-1). Low base saturation (less than 40%) shows very strong leaching of basic cations in the study area.
  E.U. Onweremadu and E.T. Eshett
  This study investigated the distribution of soil boron and its relationship with some soil properties in a sandy Paleudult polluted by crude oil in southeastern Nigeria. Three pedons representing 3 land units influenced by crude oil spillage were dug, sampled and soil samples were used for various laboratory analyses. Results showed high values of organic carbon and cation exchange capacity in spilled sites. Iron and aluminium oxides were higher in non-spilled sites and generally increased with depth. Highest values of B (0.09-146 mmol kg-1) were found in spilled land unit while soil B ranged from 0.01-0.03 mmol kg-1 in non-spilled land unit. Soil B varied widely in spilled land units but little variation was observed in non-spilled site. Higher values of correlation coefficients were recorded in non-spilled land unit than spilled site. Best predictions was found when soil pH, surface area of clay, clay content and organic carbon predictors were combined linearly.
  E.U. Onweremadu , F.O.R. Akamigbo and C.A. Igwe
  Using a free survey method in the field, five minipedons were dug in each of six soil groups based on geology/parent material identified in the study area. Three soil samples were collected from each minipedon at predetermined depths of 0-10, 10-20 and 20-30 cm. Soil Quality Morphological Index (SQMI) was used in the evaluation using texture- weighting class, structure class and rupture-resistance class as assessors. Soil samples were analyzed in the laboratory for organic carbon. Results showed that soils formed over Lower Coal Measures had the highest SQMI, followed by those formed over Alluvium, Shale, Coastal Plain Sands, Upper Coal Measures and False-bedded Sandstone. SQMI was significantly correlated with organic carbon (R = 0.55; R2 = 0.3, n = 90) at 5% level of probability, indicating that either of the two indices can be used to predict soil quality in the study area.
  E.U. Onweremadu
  Soil Quality Morphological Index (SQMI) was used to assess soil health of arable farms on soils along Otamiri River in Owerri, Nigeria. Sampled points were identified based on physiography and linked using a transect. Three minipedons were dug at equal inter-minipedal distance of 35 m and sampled. Results showed that soils on a levee had the best quality (SQMI = 3.52), followed by Terace (SQMI = 2.83), Backswamp (SQMI = 2.75) and least in Upland soils (SQMI = 2.64). Soil quality had a good relationship with organic matter (r = 0.92; r2 = 0.84; 1-r2 = 0.16; p = 0.05). Results of soil properties were used to classify soils of the site as Isohyperthermic Ruptic-Alfic Dystrudepts (USDA Soil Taxonomy).
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