The characteristics and suitability of the soils of some major cocoa growing areas of Nigeria: Tung lga of Cross River

The soils of the major cocoa growing district of Etung Local Government Area of Cross River State were surveyed using a flexible grid method to assess the  suitability of these soils for cocoa production. This study  was carried out as part of efforts to revitalize cocoa production in Nigeria. Both the linear and square root  parametric models of suitability assessment were used for the evaluation exercise. From the computed values of the current index productivity (1.80 12.75), all the mapping units delineated from the exercise were currently not suitable (N2) for cocoa production. The limiting factors identified include high rainfall (> 2500 mm annually) and relative humidity (65.5% - 85%), low fertility (N, P, K, Ca, Mg) resulting from nutrient leaching, low pH (3.45 4.90 in KCl) and cation exchange  capacity (1.67 10.75 cmol kg-1), and low to toxic  concentrations of Fe, Mn, Cu and B in the soils. However, the values of potential productivity index (13.41 - 45) suggested that most of the mapping units will be marginally suitable (S3) for cocoa production with adequate application of appropriate fertilizers and suitable soil management practices. This will require a carefully designed fertilizer trial to ascertain the optima fertilizer level, fertilizer types and application methods.Key words: Land suitability, Cocoa production, Soil fertility, Soil management and Etung LGA

Prediction Models for Water Erosion Risk Management: A Review

In order to estimate the potential soil erosion hazard of an area, erosion prediction models are needed. Various models have been used by researchers, which ranges from mathematical and conceptual simple approaches to complex models that try to include the complexities of the real world. Six (6) models are reviewed in relation to their suitability for use. The KINEROS, CORINE and EUROSEM were best suited for water erosion risk prediction in cultivated soils. On the other hand, the KINEROS, PESERA, CORINE and EUROSEM were found to be applicable in all sectors (Agronomy, water resources management and road construction) highlighted. The GLASOD had the least applicability with respect to this study.Keywords: Water Erosion, sediment transport models, Model structure and suitability for us

Suitability evaluation of Kusogi land in the sandstone-derived terrain of Niger State of Cashew (Anarcadium occidentale L.) production

Suitability of Kusogi land, in the sandstone-derived terrain of savanna ecology in Niger State, Nigeria, for cashew production was assessed. A 500 ha parcel of land originally earmarked for sugarcane production was assessed using rigid-grid method of soil survey. Aggregate actual suitability rating put three out of the five mapping units 978% of the total land area) as marginally suitable while the remaining 22% of the land was non-suitable for cashew production. Soil fertility, in terms of calcium mole fraction constitutes limitation in about 86.4% of the land and this proportion of the land was rated moderately suitable under aggregate potential suitability. Drainage and pH constitute major limitations in 13.6% of the land and aggregate potential suitability rated this as non-suitable. Climate, electrical conductivity indices and soil physical characteristics were conducive for the production of cashew. Management practices such as drainage and liming of the waterlogged parcels as well as fertility enhancement measures are recommended to elevate the current status of the land for cashew production. JARD Vol. 5 (2) 2006: pp. 140-15

The Use of Parkia Husk and Melon Wastes as Soil Amendments

A pot experiment was conducted to assess the effects of amending soil with agricultural wastes (Parkia biglobosa (Locust bean) husk (PAH), melon (Citrulus vulgaris) waste (MEW) and their mixture (PAH + MEW)) on some soil physical and chemical properties. The agricultural wastes were applied at two levels (7.5% and 10% w/w agricultural waste/soil) in a randomized complete block design. Changes in soil properties (bulk density, water holding capacity, organic carbon and available phosphorus contents) were observed over a period of 12 weeks. The available phosphorus (P) content of the soil was significantly increased (

The assessment of water quality for irrigation and sediment along Asa River

The effects of industrial, agriculture and domestic discharges on the quality of water for irrigation along Asa River located in Ilorin were assessed. In this study, Asa river in which effluent from different industries is discharged was studied for heavy metals (Cu, Pb, Zn and Cd) to ascertain its water quality for irrigation and sediment. Water and sediment samples were collected at four points used for dry season irrigation along the river. The total concentration of Cu, Pb, Zn and Cd were analyzed using Atomic Absorption Spectrophotometer (AAS) (210/211 VAP model). The range of concentration of these metals in water were Cu (1.23 5.60)mg/l, Pb (2.20-4.10), Zn (2.60-5.11)mg/l and Cd (1.80-5.01)mg/l, while that of sediment were Cu (1.80-5.09)mg/kg, Pb (2.54-5.89)mg/kg, Zn (3.84 5.21)mg/kg and Cd (3.02-6.02)mg/kg. It was found that the metals in water and sediment were above the permissible level by FEPA(1999) and W.H.O (1996). The index of salinity hazard in water was found below the FAO (1997) standard for EC (0.04-0.29) and pH (6.0-6.3) as well as U.S Salinity (1954) level for SP (0.17-0.44) %, which showed that the water was not saline. Pyrite was prominent at location three receiving effluent from a detergent and pharmaceutical industries ladened Osere river and received by Asa River. The finding showed that the quality of Asa River water for irrigation is very poor due to the high level of heavy metals in water and sediment. Consequently, the high level of metal concentration in the study area would lead to the people dependent on this river water for domestic use including cooking, bathing, washing and even drinking or for agricultural uses like fishing and farming may be exposed to public health risks. Also, the irrigated soil by this River water would influence soil processes and soil organism induction to the soil ecosystem through a reduction in the soil microbial population and the concomitant soil nutrient transformation. Similarly, due to the high level of these metals in the soil which could be transfered to the plant tissue (vegetables), their consumption could be cancerous.Keywords: Asa River, Heavy metals and salinity hazard, water quality and sediment pollutio

Some thermo-physical properties of yam cuts of two geometries

The effects of variation of temperature (-18 to 33°C) and geometries (slab and cylinder) on some thermo-physical properties of white yam were investigated. The measured parameters were density, specific heat, and thermal diffusivity at constant moisture level of 72.7% ± 0.69 (wet basis) using transient heat transfer method. Both the density and specific heat of the sample increased with increase in temperature to maximum levels after which further increase led to a reduction of the values of these parameters; however, they were independent of sample’s geometry. The rate of heat diffusion per second for the yam as measured was between 2.365 to 11.86 x 10-8 m2 and 2.676 to 8.062 x 10-8 m2 for slab and cylinder respectively. The thermal diffusivity and computed thermal conductivity were found to increase with increase in temperature. Conclusively, these thermo-physical properties were correlated with temperature using polynomials of the third order empirical model