Browsing by Author "Uzoho, B. U."

Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    Phosphorus adsorption characteristics of selected Southeastern Nigerian soils
    (Faculty of Agriculture, University of Nigeria, Nsukka, 2005-01) Uzoho, B. U.; Oti, N. N.
    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.
  • Thumbnail Image
    ItemOpen Access
    Sulphur status of selected crude oil polluted and unpolluted soils in Bayelsa, Niger delta, Nigeria
    (European Centre for Research Training and Development UK, 2017-07) Uzoho, B. U.; Okoli, N. H.; Osisi, F. A.; Ogueri, E. I.; Agomuo, C. I,; Nwadinobi, C. A.; Iwuanyanwu, U. P.; Ogueri, C. U.
    Soil sulphur status provides valuable information about its bioavailability and potential environmental consequences. Sulphur forms (total, organic, water soluble, adsorbed, organic matter bound and elemental S) of selected crude oil polluted and unpolluted soils in Bayelsa, Niger Delta, Nigeria were evaluated. Experimental design was a 3 x 2 x 2 factorial of location, soil depth and pollution status arranged in a randomized complete block set-up with 3 replications. Also relationship between S forms and selected soil properties was estimated using correlation and regression analyses. Averaged over soil depths and pollution status, soil S varied distinctly (LSD 0.05) as 1.59, 2.57 and 1.98 (elemental S), 26.25, 35.15 and 25.67 (water soluble S), 6.07, 6.34 and 6.58 (organic matter bound S), 51.71, 58.08 and 53.42 (adsorbed S), 1014.87, 998.90 and 940.13 (organic S) and 1094.92, 1092.14 and 1019.22 mg kg-1(total S) in Agudama-Epie, Elebele and Imiringi respectively. Also interactions of location x soil depths x pollution status yielded best elemental S (3.79 mg kg-1) in surface depth of polluted soil at Elebele, water soluble S (43.34 mg kg-1), organic matter bound S (10.00 mg kg 1) and adsorbed S (68.00 mg kg-1) in the subsurface depths of unpolluted soils at Agudama Epie, Imiringi, and Elebele respectively. Best organic (1228.06 mg kg-1) and total S (1296.73 mg kg-1) were in the surface depth of unpolluted soils in Agudama-Epie. Soil OM, pH, sand, silt, clay, P, N, Mg, Ca, K, Na and ECEC correlated with S forms. Besides clay whichaccounted for more than 40% of water soluble and adsorbed S, other S forms were poorly predicted by the soil properties. In general, concentrations of most S forms were higher in unpolluted than polluted soils, probably due to favourable conditions for S transformation andexistence of important S sources other than crude oil in the former than the later.