Nigerian Soils Research Articles

Design and Implementation of a Web-Based Geotechnical Database Management System for Nigerian Soils

A web-based geotechnical database management system (GDBMS) is developed for Nigerian soils. The point database (GeoDataNigeria) comprises the results of soil tests and observations from past soil investigations by different researchers and from diverse sources, with a view to maximizing the economic and scientific benefits of such test results by ensuring their unlimited accessibility. Adequate web interface is provided without limitations to all members of the public to query, report and visualize the data contained within the database. The system is designed to be infinitely extensible as managed by authorized administrators. Appropriate data templates are therefore provided for data submission while ensuring data integrity and accuracy before inclusion in the database. The data are stored raw without any pre-analysis, giving the potential users the freedom to make their own independent deductions from them. Recommendations are made to enhance the management and continual expansion of the database.

Keratinolytic activities of a new feather-degrading isolate of Bacillus cereus LAU 08 isolated from Nigerian soil

A local strain of Bacillus cereus LAU 08 was isolated from a chicken-feather disposal site in Ogbomoso, Southwest Nigeria. Production of keratinase was induced using three sources of keratin, namely: hooves, horn, and feather, at a growth temperature of 37 °C. In each case, high titers were recorded for both keratinolytic and proteolytic activities. Maximum enzyme activities were obtained within 24–96 h of cultivation, depending on the keratin substrate used and the activity under study. While maximum keratinolytic activities of 67.9, 63.1, and 51.7 U ml −1 were obtained using enzymes induced by hooves, horn, and feather, respectively, proteolytic activities of 11 860, 820, and 126 U ml −1 were obtained using enzymes induced by feather, hooves, and horn, respectively. The optimal conditions for the keratinolytic activity were determined to be pH 7.0 and temperature of 50 °C; however, the enzyme displayed more than 50% activities within the broad range of pH 7–9 and temperature of 40–70 °C. In addition, the isolate was able to completely degrade a whole chicken feather within a period of 7 days at room temperature (30 ± 2 °C). B. cereus LAU 08 is therefore a promising strain for the management of chicken feather waste through biotechnological processes.

Residence half-times of 137Cs in undisturbed surface soil in Nigeria based on measured soil concentration profiles.

The transport of fallout 137Cs within the Nigerian soil has been studied in this paper by a compartment model. The measured concentrations of the radionuclide in the soil layers were examined by the model in order to estimate the transport parameters of residence half-time and the migration velocity of the radionuclide in the soils. The residence half-times were observed to be short and decreased with soil depth with a mean ranging from 0.3 years at 0 – 2cm soil depth in Akure site to 1.4 years at 10-15cm depth in Igbeti site. The migration velocity , calculated from the residence times with the consideration of the different thicknesses of the layers were observed to decrease slowly with depth at all the sampling sites with a range from 3.62 cm y-1 at Igbeti site to 8.21 cm.y-1 at Ikogosi site. The migration velocities obtained are quite higher than those reported in literature for global fallout.

An appraisal of the capacity of Nigerian soils to sustain food self sufficiency

An appraisal of the capacity of Nigerian soils to sustain food self sufficiency

Short- and long-term effects of sparingly soluble phosphates on crop production in two contrasting Nigerian Alfisols

The effectiveness of Sokoto and Ogun rock phosphates (RP) as substitutes for the conventional phosphorus (P) fertilizer sources in the production of tomato (Lycopersicon esculentum) and okra (Hibiscus esculentus) were evaluated using single super-phosphate (SSP) as reference. Their residual effects were also investigated using rice (Oryzae sativa) and soybean (Glysine max). The two experiments were 2 × 2 × 4 factorial combinations with completely randomized design (CRD) involving two crops, two soils, three P-fertilizer sources and a control. The treatment combinations were replicated four times to give a total of 64 pots, each containing 5 kg of either a slightly acid (pH 6.3) alfisol (Typic Paleudalf) A, from Abeokuta (rainforest ecological zone) or a medium acid (pH 5.9) alfisol (Oxic Paleustalf) B, from Zaria (southern Guinea savanna zone). The soils represent a wide range of Nigerian soils with medium to low P-availability and cultivated to various food and economic crops. The rock phosphates (particularly SRP) were more efficient than SSP in soil A but had less than 50% relative agronomic efficiency (RAE) in soil B, especially when tomato was the test crop. They also had higher RAE in soil A than in soil B when okra was grown, though the efficiency was not as high as that of the reference fertilizer. In the slightly acid alfisol (A), ORP was less efficient than SRP whereas it had 47.8% RAE compared with 34.9% RAE for SRP in the medium acid soil. In the second cropping, the soil from the rainforest zone still produced greater biomass than soil B while soybean gave more biomass than rice. The results confirmed that, apart from crop species to be grown, organic matter and clay contents as well as pH of soils should be considered for efficient utilization of the sparingly soluble phosphates for both short- and long- term effects in crop production.

Geotechnical analysis of two Nigerian soils for use as clay liners

The cretaceous Auchi shale and the Tertiary Imo shale in SW Nigeria were investigated for their suitability for use as a clay seal in waste disposal landfills. Geotechnical analyses indicated they are highly plastic inorganic clays. Although their geotechnical and chemical properties were within the range suggested by various authors for use as mineral seals, care would need to be taken with the Okada shales as they contain smectite and would be difficult to work and liable to cracking.

Distribution of magnesium forms in surface soils of Central Southern Nigeria

The distribution of various Mg forms in selected surface soils of the Edo State of Central Southern Nigeria was studied to contribute for a basic understanding of where and in what fractions Mg was located. Twenty surface (0 – 15cm) soil samples collected from pre-classified sites were investigated. The various Mg forms were determined by fractionation. Exchangeable [Mg(e)], organic complexed [Mg(o)], acid-soluble [Mg(a)], mineral [Mg(m)], and total [Mg(t)] ranged from 0.64 – 2.10, 0.12 – 0.63, 2.52 – 5.25, 2.94 – 5.04 and 7.35 – 12.60 cmol kg−1 with means of 1.36, 0.33, 3.69, 3.86 and 9.65 cmol kg-1, respectively. The Mg(o) averaged less than 3.42% of the Mg(t) in the soils. Mg(t) content of the soils appeared to be influenced by parent materials. The amounts of the various chemical forms of Mg could be ranked in terms of abundance in soils in the following order: Mg(m) > Mg(a) > Mg(e) > Mg(o). Mg(a) was positively and significantly correlated with Mg(m) and Mg(t) (P ≤ 0.05) while Mg(m) was positively and significantly correlated with Mg(t) (P ≤ 0.001). The soils were adequate in Mg(e) based on established critical levels for Nigerian soils.

Horizontal infiltration and trace element measurements for Savannah soils in Zaria, Nigeria

Laboratory investigations of horizontal infiltration were carried out on three Zaria soils (Samaru, Tudun Wada and the Kubanni river basin Fadama wet-land soils) in Nigeria, which are principally alfisols. Diffusivity was found to be -77.5 x 10 -2 cm 2 s-1, -8.4 x 10 -2 cm 2 s-1 and -117.0 x 10 -2 cm 2 s-1 respectively for the three soils. Other infiltration characteristics including, sorptivity and water flux through the soils were also measured.. Concentration data for twenty-one elements ( Sb, Ba, Ce, Co, Cr, Cs, Eu, Hf, Fe, La, Lu, Nd, K, Rb, Sc, Na, Ta, Th, U, Yb, Zn) were also determined for the three soils. The study revealed that although the mineralogy of the soils appeared similar based on their mean elemental compositions, the Fadama soils showed high sorptivity, indicative of water-logged conditions which is characteristic of wet-lands. Keywords: Nigerian Soils, Darcy\'s equation, infiltration, ko-standardization, neutron Activation analysis Nigerian Journal of Physics Vol. 18 (1) 2006: pp.13-18

Solubilization of Insoluble Phosphate by Organic Acid-Producing Fungi Isolated from Nigerian Soil

Solubilization of Insoluble Phosphate by Organic Acid-Producing Fungi Isolated from Nigerian Soil

Nutrient Element Contents and Cation Exchange Capacity in Fine Fractions of Southeastern Nigerian Soils in Relation to Their Stability

Soils collected from 15 locations from SE Nigeria at the 0‐ to 20‐cm depth were studied for the nutrient elements of fine fractions and their role in the stability of the soils. The objective was to understand the role of these elements in the stability of the aggregates. The fine fractions were clay and silt, and elements measured in the fine fractions were exchangeable sodium (Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), exchangeable acidity (EA), cation exchange capacity (CEC), and available phosphorus (P). The aggregate stability was measured at the microlevel with clay dispersible indices and water‐stable aggregate (WSA) <0.25 mm, and at macrolevel with other WSA indices and mean‐weight diameter (MWD). Soils varied from loamy sand to sandy clay. There were more exchangeable cations, CEC, EA, and available P in clay than in the silt fraction. Whereas EA values ranged from 2.8 to 10.4 cmol kg−1, they were between 1.6 and 9.2 cmol kg−1 in silt. The CEC in the clay fraction was from 7.4 to 70 cmol kg−1 and between 4.0 and 32.8 cmol kg−1 in the silt fraction. The WDC were from 50 to 310 g kg−1 while the average dispersion ratio (DR) was generally higher than the corresponding clay‐dispersion ratio (CDR), and the MWD ranged from 0.45 to 2.68 mm. Soils with WSA skewed mostly to higher WSA (>2–1.00 mm) had a higher MWD. Exchangeable Ca2+ in clay correlated significantly with CDR and WSA sizes 1.0–0.5 mm and 0.5–0.25 mm (r=0.45,* 0.51,* and 0.60*), respectively, but negatively correlated with clay flocculation index (CFI) (r=−0.45*). Also, available P in clay correlated respectively with CDR and CFI (r=0.45*, −0.45*), whereas K+ in silt correlated significantly with WDSi (r=0.64*), CFI (r=0.62*), and CDR (r=−0.65*). Principal component analysis revealed that elemental contents in the silt fraction can play very significant roles in the microaggregate stability.

Phosphorus adsorption characteristics of selected southeastern nigerian soils

The phosphorus adsorption characteristics of selected Southeastern Nigerian soils from Ikom, Bende and Ihiagwa were evaluated. P adsorption isotherm was obtained by shaking soil samples with 0, 10, 20, 30, 40 and 50 ppm P in 0.01M CaCl2 solution. P adsorption maxima (b), affinity constant (k), buffering capacity and P sorbed at 0.2 ppm equilibrium solution were estimated. Also adsorbed P was correlated with some soil properties. The adsorption isotherm showed that the capacity to adsorb phosphorus varied in the order; Ikom> Ihiagwa> Bende. The values for the P sorbed at 0.2 ppm solution, buffering capacity, adsorption maxima and affinity constant were 43.28, 43.30, 34.48 and 12.95 ug/g respectively for Ikom, 3.86, 7.78, 29.50 and 0.21 ug/g respectively for Bende and 8.48, 10.00, 33.11 and 0.57 ug/g respectively for Ihiagwa soils. The capacities to adsorb P was significantly and positively correlated with soil clay (r = 0.94), exchangeable aluminum (r = 0.72), soil pH (r = 0.83), whereas the correlation with exchangeable calcium (r = -0.56) and organic carbon (r = -0.72) were significantly negative. The implications are that the higher the soil pH, clay level, exchangeable aluminum, adsorption maxima and affinity constants the higher the soil adsorption capacities whereas the reverse will occur the higher the soil organic carbon and calcium levels. The study shows that Ikom soil will require higher P fertilization rates than the other two soils for optimum plant growth. Also management practices involving the use of organic matter and liming as basis for P adsorption reduction would be useful for improved crop production in these soils. The use of P adsorption isotherm as a valid tool for P fertilizer management is recommended for Southeastern Nigerian soils.Agro-Science Vol. 4 (1) 2005: pp. 50-55

Effect of animal manure incorporation on erosion indices of two Nigerian agriculture soils

Effect of animal manure incorporation on erosion indices of two Nigerian agriculture soils

Determination of phosphorus requirement of cowpea using P-sorption isotherm

The P requirement of cowpea in Ikom (Lat 60 50'N, 8 ° 15'E), Bende (50 42'N, 7 ° 44'E) and Ihiagwa (5 ° 21'N, 7 ° 15'E) in Southeastern Nigeria were estimated using the P-sorption isotherms. Soil samples were shaken in graded solutions of P (0, 10, 20, 30, 40, and 50 ppm P), and the P sorbed at 0.2 ppm equilibrium solution P concentration and that required to saturate the adsorption complex of the soils were estimated from the sorption isotherm. Cowpea was grown in polyethylene bags and four P rates representing: (1) Control, (2) P required to attain 0.2 ppm equilibrium solution P concentration, (3) P required to saturate the adsorption complex plus 15 kg P/ha (usually recommended P rate for cowpea fertilization in Southeastern Nigerian soils) and (4) P required to saturate the adsorption complex plus 12 kg P/ha (4 kg P/ha less than the usually recommended P rates) were added. The polyethylene bags were arranged in a randomized complete block design with four replications. The P sorbed at 0.2 ppm equilibrium solution concentrations were 103 ug/g P for Ikom, 9 ug/g P for Bende and 19 ug/g P for Ihiagwa. The P required to saturate the adsorption complex of the soils were 30 kg/ha, 4 kg/ha and 9 kg/ha for Ikom, Bende and Ihiagwa soils, respectively. The P fertilizer rates required for cowpea production in the soils were 45 kg/ha, 19 kg/ha and 19 kg/ha for Ikom, Bende and Ihiagwa soils, respectively. The study shows that the capacity to adsorb P in the soils is low in the order Ikom > Ihiagwa > Bende and suggesting that only a small amount of P fertilizer shall be required for optimum cowpea production in these soils. Organic matter and liming as management practices shall be useful for P fertilizer utilization in the soils since they enhance plant available P by depressing phosphorus adsorption. The use of P-isotherm technique for phosphorus fertilizer determination is therefore, recommended for efficient P fertilization practice in Southeastern Nigerian soils. Keywords: P-sorption isotherm, organic matter, liming, cowpea International Journal of Agriculture and Rural Development Vol. 5 2004: 77-85

Comparison Of Six Extractants For Assessing Available Phosphorus, Zinc And Manganese In Selected Nigerian Soils

Interactions between soil available phosphorus (P) and micronutrients [particularly zinc (Zn) and manganese (Mn)] are becoming increasingly significant for sustainable crop production in many countries of the world (including Nigeria) with highly weathered acid or calcareous alkaline soils. The nutrient extraction methods in use consume time and many other resources. In this work, the relative suitability of six extractants [Deionised-H2O, 1 N NH 4 OAc, 0.1 M HCl, 0.01 M CaCl 2 , Bray-1 and electro-ultra-filtration (EUF) technique] for simultaneous assessment of the availability of these nutrients in selected Nigerian soils was evaluated using guinea-corn (Sorghum bicolor) as test crop in Neubauer experiment. The respective average amounts of P, Zn and Mn extracted by 1 N NH 4 OAc (63.86, 12.6 and 50.12 mg/kg) are about six-, three- and five times more than those of deionised-H 2 O (10.09, 4.06 and 5.03mg/kg) which constituted only 0.49, 0.18 and 0.10% of total P, Zn and Mn, respectively in the soils. Phosphorus was the least extracted element, highest mean value being 22.66mg/kg (Bray-1) compared with 155.31mg Mn/kg and 33.56mg Zn/kg. The EUF technique extracted the greatest amount of Zn, followed by 0.1 M HCl, 1 N NH 4 OAc, Bray-1, deionised-water and 0.01 M CaCl 2 . One-tenth N HCl extracted about 70%, 76.5%, 81.5%, 87.6% and 100% more Mn than 1 N NH 4 OAc, Bray-1, 0.01 M CaCl 2 , EUF technique and deionised-water, respectively. The water-soluble (deionised-H 2 O extractable) and exchangeable (1 N NH 4 OAc – extractable) nutrient forms were poorly correlated with plant parameters whereas the relationship between the plant parameters and P or Mn extracted by the different methods showed that the EUF technique could be used to assess P and Mn availability in the soils. One percent M CaCl2 was observed to be best for assessing Zn availability to the sorghum plants. It was quite obvious that none of the extraction procedures tested could be successfully employed as a multipurpose extractant for available-P, Zn and Mn. KEY WORDS: Multipurpose extractants, Electro-ultrafiltration technique, Phosphorus, Zinc, Manganese. Global Journal of Pure and Applied Sciences Vol.11(2) 2005: 179-184

Degradation Characteristics and Management of Marginal Lands in Nigeria, Africa

DOI: http://dx.doi.org/10.0165/jss2005.02.003 Many Nigerian soils are highly degraded and weathered, heavily leached and have limited capacities for supplying the plant nutrients and for holding enough moisture needed for high productivity, they are therefore ‘marginal’. Swamps, marshes, hills, mountains and uncultivated marginal lands are always in danger of erosion, drought and low structural stability and compaction. Generally, marginal lands do not guarantee sustainable cultivation without external inputs. However, Nigerian farmers continue to crop the marginal lands because of increasing population growth and the use of agricultural lands for housing, roads, industry and other activities. An attempt was therefore made to discuss some elements for marginal lands for high productivity and sustainability.

Use of a Polyacrylamide Soil Conditioner in Stabilizing Nigerian Dune Soils

The effect of a Polycrylamide soil conditioner on crust strength, aggregate stability to water, bulk density and porosity and soil availability water in sand, loamy sand and sandy clay loam was investigated in the laboratory using six application rates, viz, 0.5, 1.0,1.5,2.0,2.5 and 3.0 kgm-3. There were no significant differences among the treatments for crust strength. The soil conditioner also had no effect on bulk density and porosity, aggregate stability to water and soil available water in loamy sand and sandy clay loam. In sand, bulk density decreased and porosity increased with application rate, respectively, while the rate of 1.0 kgm-3 was found suitable for aggregate stability. Soil available water in sand increased with application rate. The soil conditioner was found suitable for sand dune fixation. 1 ICP Physical Land Resources, Ghent University, Coupure Links 653, B-9000 Gent, Belgium. Email: scj922@yahoo.com

COMPARATIVE EFFECTIVENESS OF WATER, CALGON AND SODIUM HYDROXIDE IN SOIL DISPERSION UNDER TWO MECHANICAL AGITATION METHODS

Distilled water, 5% calgon and sodium hydroxide were used as dispersion agents in the particle size analysis of surface and subsurface soils of five Nigerian soils. Sampling depths were 0 – 15, 15 – 30 and 30 – 45cm and concentrations of sodium hydroxide were 0.2N, 0.4N and 0.6N respectively. Agitation methods were high speed mechanical stirring for five minutes, and overnight shaking on a reciprocate shaker. Water was found to be least effective in soil dispersion, regardless of sampling depth or agitation method. There was no significant difference between the effectiveness of calgon and different concentrations of NaOH (p= 0.2866). There was also no significant difference between the two agitation methods within each soil depth. There was however highly significant interaction between soil depth and agitation method (p [Niger Agric. J. 34 (2003): 19-26]

Carbohydrates and aggregation in lowland soils of Nigeria as influenced by organic inputs

We evaluated the influence of several organic matter management practices on the characteristics of carbohydrates in water-stable aggregates and soil aggregate stability at three Nigerian locations (Abakiliki, Nsukka and Umudike) where forests had been converted to arable farming. The effect of management practices to enhance aggregate stability was site-specific. The highest aggregate stability was obtained with Gliricidia sepium at Abakiliki, with Cajanus cajan followed by rice mill wastes (RW) at Nsukka and with the forested soil at Umudike. While none of the treatments at all sites was able to enhance the C and N contents of the soils to the levels obtained in the forested sites, a net improvement in carbohydrate and organic carbon (OC) content was found for some management practices. The carbohydrate status increased with G. sepium at Abakiliki, and with Dactylodenae bacterii alone or in combination with Pentaclethra species at Umudike, while at Nsukka all organic inputs increased carbohydrate content over the control and forested soils. However, neither total OC nor the carbohydrate content were significantly correlated to the variability in aggregate stability of these soils. The δ 13 C values found for acidic hydrolysates were constant within the soil aggregate sizes and generally distributed around −29 to −30‰, suggesting that the OC from these sites originated from C3 plants. Our results indicate that in these tropical Nigerian soils, aggregate stability and OC content are generally preserved by alley-cropping in well structured soil, whereas treatments with organic wastes are sustainable management practices in more fragile soils.

Effect of Forage Legume Incorporation on Selected Soil Chemical Properties in the Northern Guinea Savanna of Nigeria

ABSTRACT The Nigerian savanna soils are low in fertility, organic matter and cation exchange capacity. The traditional method of improving the fertility and productivity of soils of the savanna is through natural fallowing which typically takes three to five years. The method is no longer suitable for most farmers because of the rapid growth of population in developing countries and the resulting intensive cultivation of agricultural land. In this study, a short fallow technique was adopted using forage legumes. Selected soil chemical properties were also evaluated. Incorporation of most of the legume residues significantly (P < 0.05) increased soil organic carbon more than control treatment especially when 5.0t ha−1 of organic matter is incorporated. The application rate of 5.0 t ha−1 gave higher soil organic carbon content than the 2.5 t ha−1 rates. However, the incorporation of maize stover and legume residue resulted in significantly higher soil organic carbon than the initial rate of 5.65 g kg−1. Exchangeable cations were increased by the legume incorporation more than in the control. The impacts created by legume incorporation were mostly felt at the topsoil (0-15 cm). Adoption of the technology might be hindered by the fact that these legumes do not have immediate food grain benefit like the grain legumes (i.e., cowpea and lablab). The fallow legumes and food crops could be intercropped either simultaneously or in a relay pattern with cereal (maize or sorghum) to improve productivity of the land for sustainable food crop production.

Responses to rhizobial inoculation by two promiscuous soybean cultivars in soils of the Southern Guinea savanna zone of Nigeria

TGX soybean lines were bred at IITA Ibadan for promiscuity with indigenous rhizobia in Nigerian soils. Two cultivars, TGX1456-2E and TGX1660-19F, were tested in a 2-year trial for their response to rhizobial inoculation in five farmers' fields within a 60-km radius of Minna town, in the Southern Guinea savanna zone of Nigeria. Using the ELISA method, the competitiveness and persistence of the two elite strains of rhizobia contained in the inoculant mixture were also studied. There was a close relationship between nodulation and the size of resident rhizobial populations, with wide variation in nodulation across the various sites irrespective of the treatments. Cultivar effect on height and nodule number was significant only in the first cropping season of the trial. The inoculant strains appeared to be less competitive, but more effective, than the indigenous populations. The proportions of the nodules occupied by the inoculant strains were 17% in the first cropping season, and 24% in the second. Inoculation with rhizobia increased the percent arbuscular mycorrhizal infection by an average of 50%. Although grain yield varied between sites, no significant cultivar effect was observed. However, inoculation increased grain yield by 40% in the first cropping season, while no such yield differences occurred in the second season. The proportion of nitrogen derived from N2 fixation ranged from 27% to 50% in both cropping seasons, and this was dependent on crop management on farmers' fields, rather than any cultivar or inoculation effect.