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Articles by E.U. Onweremadu
Total Records ( 20 ) for E.U. Onweremadu
  E.U. Onweremadu
  This study investigated the distribution of soil carbon in two slope aspects of a hilly landscape in Southeastern Nigeria. A transect was used to align soil profile pits dug on three physiographic positions of crest, midslope and footslope on both slope aspects. Soil and core samples were collected from pedogenic horizons based on soil profile differentiation. Standard analytical and statistical tools were used to analyze soil samples and data, respectively. Results showed that less values of soil carbon were recorded in soils of the windward side despite its forested nature. Organic carbon (OC) decreased with depth in both slope aspects while inorganic carbon (IOC) had higher values in deeper layers. Bulk density decreased as organic carbon increased in soils of the study site. Soils on the windward landscape had higher erodibility values based on calculated Dispersion Ratio (DR) values. Better relationship existed between soil carbon and DR on leeward aspect of the hilly landscape when compared with values of the same parameters in soils of the windward side of the study area.
  E.U. Onweremadu
  Responses of Amaranthus caudatus to application of ground seashells (GSS) and Rabbit Dung (RD) on erosion-degraded ultisols were studied. Three experiments were conducted from April to June, 2006 in three locations of Owerri, Southeastern Nigeria for this purpose, using 7 manurial treatments, namely control, 2 t ha-1 GSS, 8 t ha-1 RD, 2 t ha-1 GSS+2 t ha-1 RD, 2 t ha-1 +4 t ha-1 RD, 2 t ha-1 GSS+6 t ha-1 RD and 2 t ha-1 GSS+8 t ha-1 RD. These treatments were replicated thrice in a Randomized Complete Block Design (RCBD). Combinations of GSS and RD increased growth and yield parameters of Amaranthus caudatus with 8 t ha-1 RD, 2 t ha-1 GSS+4 t ha-1 RD and 2 t ha-1 GSS+8 t ha-1 RD giving higher fresh matter yield of 55.2, 49.1 and 77.0 t ha-1, respectively.
  E.U. Onweremadu
  Variability of soil carbon in 5 floodplain soils at landscape scales were studied. Transect technique was used in soil sampling at 0, 25, 50, 75 and 100 m sampling points. Results showed that some measured soil properties varied among floodplain soils although all locations belong to the rainforest agro-ecology. The Oa horizons accounted for the highest variability in thickness (CV = 26%) in some locations. There was significant variation in total soil carbon in 60% of the floodplain soils. It is concluded that intensive soil sampling from landscape delineations will provide more accurate and reliable representation of soil carbon for scaling at regional levels.
  C.I. Duruigbo , J.C. Obiefuna and E.U. Onweremadu
  This study was conducted to determine the effect of poultry manure rates on soil acidity at the Federal University of Technology Research Farm Owerri. The experiment was laid out in randomized complete block design with three replications. Four poultry manure rates namely: 0, 5, 10 and 15 t ha-1 were used in the study. The soil physical and chemical status before and after application of poultry manure were analyzed. The chemical compositions of the poultry manure was analyzed. All data collected was subjected to analysis of variance according to the General linear model in statistical analysis software (SAS). Results indicated that application of poultry manure at the rate of 15 t ha-1 significantly increased soil pH from 4.14±0.9 (control) to 5.80±0.23 (pH in water) and from 3.62±0.13 to 5.78±0.18 (pH in KCl), respectively. Poultry manure rate of 5 t ha-1 did not significantly increase soil pH.
  E.U. Onweremadu
  The major aim of this study was to investigate the availability of soil nutrients under different land uses and landscape positions. Three hillslopes were used for the study and soil sampling was guided by the transect technique. The soil samples were collected in May 2004, July 2004 and July 2005. Five soil nutrients, namely Total Phosphorus (TP), Available Phosphorus (AP), Total Nitrogen (TN), Available Nitrogen (AN) and Soil Organic Matter (SOM) were analyzed and used for the study. Data were statistically analyzed using analysis of variance (ANOVA) and mean comparisons were made using Least Significant Difference (LSD). Results showed significant (p<0.05) differences in SOM, TN and AN among land uses. Heaviest soil deterioration was recorded in soils under Pineapple Orchard (PO) and least in Grassland (GL) soils. There were significant (p<0.05) differences in soil nutrients due to landscape positions especially in Hillslopes B and C. Surprisingly, values of soil nutrients were higher in middle slopes of Hillslope C unlike in the other two where such occurred in the footslopes. The SOM had very great influence on AP and AN.
  E.U. Onweremadu and M.A.N. Anikwe
  This study was conducted from September 2005 and February 2006 to investigate wettability properties of soils on a catena in the humid tropics. A transect technique was used to align pedons on three identifiable forested physiographic positions. Soils were classified as Typic Paleustult/Dystric Nitisols. Soil samples were used to determine Soil Organic Matter (SOM), water [SOM (W)] and sodium pyrophosphate [SOM (PY)] soluble SOM fractions. Hydrophobic (A) and hydrophilic (B) functional groups of bulk soil SOM and soluble fractions were assessed with Fourier-Transform Infrared (FT-IR) spectroscopy. Soil wettability increased when Soil Organic Carbon (SOC) contents were less than 14 g kg-1 while it decreased for SOC contents greater than 14 g kg-1. The Contact Angle (CA) of footslope soil was largest at Bt3 horizon but with smallest SOC (1.6 g kg-1) content.
  E.U. Onweremadu
  The study investigated the composition and distribution of basic cations in soils formed over different lithologies in lowland states of Southeastern Nigeria. Field and Laboratory studies were conducted in 2004 using routine methods. Soil data were subjected to analysis of variance (ANOVA) statistic using the PROC Mix-model of SAS computer package and means were separated by standard error of the difference (SED) at 5% level of probability. Results showed significant (p<0.0001) differences in the distribution of exchangeable calcium (Ca2+) and potassium (K+) among soil groups while the 4 basic cations: Ca2+, K+, magnesium (Mg2+) and sodium (Na+) differed significantly (p<0.0001) among horizons. Highest basicity (base saturation = 434.40 g kg-1) was recorded in soil formed over coastal plain sands while Bt3 horizon had the highest base saturation (438.00 g kg-1) among horizons. Elemental ratios showed highest Ca/Mg ratio of 8.60 in soil derived from Shale, with Alluvial-formed soil having the highest (Ca2+ + Mg2+)/(Al3+ + H+) ratio of 1.39. There were strong relationship (p<0.05) between exchangeable basic cations and sand and silt contents. Buffering capacity dynamics of these basic cations should be studied for more comprehension and usage of these soils for sustainability.
  E.U. Onweremadu
  A field study was conducted in the months of March, April and May 2006 to investigate variability in P-forms in soils derived from 4 different parent materials, namely coastal plain sands, shale, basement complex rocks and a mixture of cretaceous sandstones and shales. A free survey approach was used in setting soil profile pits. Soil samples were prepared for Laboratory analysis. Variability was established in soil groups using Coefficient of Variation (CV) while relationship existing between P-form and soil properties was ascertained by correlation analysis. Results indicate that occluded P was the most abundant P form and this is environmentally unhealthy. Iron-P and aluminum-P predominated over calcium P, Most P-forms showed slight to moderate variation (CV≤50%). Clay content had significant correlation (p<0.05) with P-forms hence can be used as a reliable predictor of variability of P-forms.
  C.C. Opara , E.U. Onweremadu and I.I. Ibeawuchi
  The study was conducted to investigate effects of different application rates of Rabbit (Oryctolagus cuniculus) Waste (RW) on the water stability of peds (natural aggregates) of three soil types-entisol, inceptisol and ultisol collected from Nsukka, Adani and Ihiagwa (Owerri) respectively in Southeastern Nigeria. Aggregate stability was measured at the macro-level by Mean Weight Diameter (MWD) index and micro-level by Aggregated Silt plus Clay (ASC%) index. From each location, samples were randomly collected from four points or spots and bulked for determining aggregate stability indices and other soil properties. Results obtained revealed that with MWD (mm) index and using LSD (0.05) value of 0.04 for comparing mean values among the soils (A), ultisol was statistically greater in stability than the other soil types. The stability order was ultisol (0.49 mm) >inceptisol (0.42 mm) >entisol (0.213 mm). Similarly, with LSD(0.05) value of 0.02 for the RW rates MWD obtained at 100 g/2 kg soil was significantly higher than MWD of other rates. The magnitude of improvement in structural stability following increased application rates of RW was however dependent on the soil types or vice versa as indicated by the statistically significant (p≤0.05) soils (A) X RW rate (B) interaction. Using ASC (%) index and LSD(0.05) value of 1.08 to compare mean values of ASC among the soils (A), the stability of inceptisol was statistically greater than other soil types and was in the order: inceptisol (30.39)> entisol (14.23) > ultisol (5.67). Also, with LSD(0.05) values of 0.38 for comparing the mean values of RW rate, the ASC(%) obtained at 100 g 2 kg-1 soil was statistically higher than as obtained at other lower rates. The magnitude of improvement in aggregate stability was however a function of the soil types or vice versa as revealed by the statistically significant (p≤0.05) soil (A) X RW rate (B) interaction.
  C.N. Mbah , M.A.N. Anikwe , E.U. Onweremadu and J.S.C. Mbagwu
  The structural stability of soils has an impact on a wide range of processes that influence crop growth. This study evaluated the role of soil organic matter (SOM) and carbohydrate pools of soil organic matter (cold water, hot water and dilute acid soluble) on the structural stability of organic waste amended dystric leptosol in Abakaliki area southeastern Nigeria. The wastes used for soil amendment were Poultry Droppings (PD), Cow Dung (CD), Sewage Sludge (SS) and Swine Waste (SW) applied at 0, 10 and 20 Mg ha-1 concurrently for two years. The results of the study showed that SOM was significantly higher in waste amended plots than in the control by 122-179 and 166-226% in the first and second cropping seasons, respectively. Observed mean increase in soil carbohydrate content was 169 mg kg-1 (cold water soluble), 476 mg kg-1 (hot water soluble) and 593 mg kg-1 (dilute acid soluble) in the first cropping season. In the second cropping season 193% (cold water soluble), 86% (hot water soluble) and 93% (dilute acid soluble) increase were observed relative to the control in the second cropping season. Aggregate stability correlated positively (r = 0.68*) with SOM and poorly with soil carbohydrate (cold water, hot water and dilute acid soluble) content. The results from this study showed that SOM contributes to soil aggregate stability whereas the soil carbohydrate pool was not effective in aggregation of the soil studied.
  E.U. Onweremadu and M.A.N. Anikwe
  Responsiveness of soils to volume change at all moisture statuses affect infrastructural development of soils. Volume Shrinkage (VS) was estimated from Coefficient of Linear Extensibility (COLE) values, using 150 soil samples from 30 soil profile pits in southeastern Nigeria. The objective of this study was to use soil properties related to shrinkage in predicting and monitoring volume changes in these soils in southeastern region of Nigeria. The value of liquid limit (26-30%) was higher than that of plastic limit (11-13%). Plasticity index was lower (16-17%) in the upper soil layer (0-40 cm) than in the lower horizons (41-80 cm layer) by 24%. Volume shrinkage value (11.20-11.80%) was least at the topmost horizon (0-40 cm depth) and increased to between 14-18% in the lower part of the profile (40-100 cm). Soils at all depths showed low to moderate shrink-swell properties having coefficient of linear extensibility of 0.036-0.057 cm cm-1 with middle layers showing higher shrink-swell characteristics. These results show moderate shrinkage (VS = 10-20) although intra-pedal variability was prominent. Multiple regression analysis showed good predictive ability (R2 = 0.76): p = l.05; n = 150) of Atterberg’s limits, texture, bulk density and organic matter (OM) in determining shrinkage properties. Accuracy of prediction was defined by a low Root Mean Square Error (RMSE) value of 0.01 while the model overestimated slightly (bias±0.00001).
  Ibeawuchi, I.I , E.U. Onweremadu and N.N.Oti
  The number of leaves per plant increased with increase in poultry manure rate. Applications up poultry manure at all rates in the entire plots generated high weed yield that the control plots were significantly lower (p 0.05) than plots with poultry manure. Weeds were suppressed because the control plots were degraded and had low soil fertility. After the experiments, the plots with poultry manure were more fertile than the control plots. Thus, there were increases in soil N (0.84%), organic matter (3.93%) P (13.45ppm), while the exchangeable cations K (0.76), Ca (0.71) and Mg (0.63) Cmol (+) kg-1, respectively. The high organic matter percentage, with increase in the other soil chemical components, it is an indication that poultry manure has high potential of gradual nutrient release to the soil that can help to improve the fertility of a degraded soil; thereby sustaining yield under-continuous cropping system.
  E.U. Onweremadu , C.C. Asiabaka , O.M. Adesope and N.S. Oguzor
  This study investigated the applicability of soil survey information on land use activities in Abia and Imo States, Southeastern Nigeria. Data were collected through the use of structured interview schedule. Simple percentages were used to analyse data. The findings revealed that soil colour (28%) and soil organic matter (27%) were known by farmers. Land use for residential homes (44%) and farming (38%) dominated other land use types. Fallowing (40%), mulching (13%) and terracing (10%) were popular soil conservation practices. Soil survey information was scarcely used in all the land use activities. It is therefore recommended that extension agents should help farmers with scientific information to complement their indigenous knowledge. It is only through this that progress can be made in effective land use.
  I.I. Ibeawuchi , J.C. Obiefuna , M.C. Ofoh , G.O. Ihejirika , C.T. Tom , E.U. Onweremadu and C.C. Opara
  An evaluation of four soybean varieties namely TGX 1440-IE, TGX 1485-1D, TGX 1805-17F and Samsoy I, intercropped with Okra NHAE 47-4 was conducted in the ultisol of Owerri south eastern, Nigeria in 2001 and 2002 cropping seasons. Samsoy I, was significantly different (p<0.05) in height, number of branches and economic yield from other soybean varieties studied. Again Samsoy I and TGX 1485-ID were significantly different (p<0.05) from TGX 1440-IE and TGX 1805-17F in terms of total dry matter yield (TDMY) nodule weight (mg/plant) and nodule number, indicating a high potential for N-fixation in the Owerri ultisol. Okra showed no significant effect as it performed uniformly both in height, branching habit and economic yield. The highest economic yield (1.2 t ha-1) and monetary value (N78,500.00 ha-1) was obtained by intercropping Samsoy I+okra. The crop combinations were not effective in suppressing weeds, therefore care has to be taken to keep all plots weed-free.
  E.U. Onweremadu
  Aided by a reconnaissance visit, a geological map of southeastern Nigeria was used in January 2006 to identify 6 soil groups based on parent material. A free survey method was used and 5 pedons were sited on each soil group. Routine Laboratory analyses were performed on collected soil samples. Results indicate variability in the suitability of soils for the disposal of waste products. There was higher tendency of surface water flooding in soils formed over shale when compared with other soil groups. Gravimetric soil moisture, bulk density, organic matter and soil texture influenced suitabilities for waste disposal. However soil textural characteristics dominated and related significantly (p = 0.01; 0.05) with other soil properties. Principal Component Analysis (PCA) is needed to identify most influential variables and such may be used to attempt a model for waste disposal in the study area.
  E.U. Onweremadu
  The effects of automobile and municipal solid wastes on soil mercury (Hg) distribution were studied in soils of a toposequence at Nekede, Southeastern Nigeria in 2005. Three pedons representing 3 physiographic units of the site namely Upper Slope (US), Lower Slope (LS) and Foot Slope (FS) were aligned and dug along a transect. Results show that heaviest concentrations of Hg were reported in epipedal and subsurface horizons in LS land unit. Highest values of Hg concentration was found in the surface layers in all land units. Minimal Hg concentrations were recorded in the FS soil classified as Fluvaquentic Eutropept (Eutric Fluvisol). Soil organic carbon, CEC, pH and texture had significant correlations with Hg using the available data hence reliable predictors of Hg distribution and availability. There is need to evaluate uptake of Hg by common crops of the study area since epipedal contents were above critical limits.
  E.U. Onweremadu and A.E. Ibe
  Influence of clay type and sesquioxides on the distribution of mercury (Hg) in a soilsphere in southeastern Nigeria was studied in 2006. A base map derived from geological map of the study area guided field sampling. Routine and special analyses were conducted on soil samples for the purpose of this study. Soil data were subjected to statistical analysis using SAS computer software. Results showed that Ibeku soils were younger, had more sesquioxides with crystalline forms dominating the amorphous oxides. Similar trend was followed by older Umuahia soils. Hemiexpansible minerals and smectites were dominant clay minerals in Ibeku soils unlike Umuahia soils dominated by kaolinite. Higher values of Hg were recorded in the Ibeku soils (9.2-15.6 mg kg-1) compared with Umuahia soils (5.6-8.1 mg kg-1). Degree of relationship between Hg and soil properties differed. While organic matter (R = 0.92), hemi-expansible minerals (R = 0.91) and oxalate iron (Feox) (R = 0.88) influenced Hg distribution in Ibeku soils, kaolinite (R = 0.89) and Feox (R = 0.89) had the highest influence over Hg contents in pedogenic horizons of Umuahia soils. More information on Hg forms, dispersability and flocculation properties of these soil colloids and edaphic factors influencing them are needed for practical usages in agriculture and environment.
  E.U. Onweremadu , D.O. Asawalam and A.E. Ibe
  Growing sewage sludge production in urban and peri-urban areas in Nigeria without hygienic disposal necessitated this study. Three experiments were conducted in 2004-2006 cropping seasons at the Teaching and Research farm of the Federal University of Technology Owerri, Southeastern Nigeria for the purpose of investigating the effects of composted sludge on soils of the area and yield of Amaranth (Amaranthus cruentus L.). Rates of compost application were 0, 2, 4, 6 and 8 t ha-1 and with 3 replications in a Randomized Complete Block Design RBBD. Results indicated significant (p<0.05) increases in crop performance and reduced cadmium and mercury concentrations in composted sludge when compared with the un-composted sludge. Soil properties were highly improved as residual effects of composted sludge.
  E.U. Onweremadu
  The morphological, physical and chemical changes taking place in fine earth materials proximal to Onyema coal mine in Enugu Southeastern Nigeria were studied in 2006 using routine techniques. Anisotropy among soil properties were determined using Coefficient of Variation (CV) measured in percentages. Results indicate formation of cambic (Bw) horizons, presence of carbolithic materials and prominence of rock fragments (25-60%). Soils were more grayish in horizons closest to consolidated basement rocks. There were little to moderate variations in soil properties except in silt-clay ratio (CV = 48-76%) and silt content (CV = 37.4-69.0%). Total sulphur content and soil pH increased with depth as underlying soil were poorly drained. Aluminium saturation (Alsat) was high in both mine soil sites (Alsat = 38-71%). Soils were classified as Typic Dystrudepts (Dystric Anthrosols) in Pedon I while Oxic Dystrudepts (Dystric Anthrosols) in Pedon 2. The use of geostatistical and pedometric techniques is suggested for modelling for sustained use of soils for agriculture and environment.
  E.U. Onweremadu
  Selected soil properties and concentrations of aerial pollutant gases of a pip pen environment were investigated at the on-set of rains in 2005. A free survey technique was used in the study. Results revealed that soils are highly weathered (very low silt-clay ratios) and differed greatly at epipedons. Carbon monoxide (CO) had a good relationship (R2 = 0.54; p<0.05) with clay content and soil pH. Similar result was recorded when these soil properties were regressed to methane (CH4).These results present clay content and pH as good predictors of gas emission status in a livestock environment (R2 = 0.51) at p<0.05. Aerial pollutant gases concentrations were relatively low but there is need to study the temporal viabilities of these gases.
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