Water quality assessment of Owiwi River for potential irrigation of vegetables

Understanding water quality used for irrigation and its potential negative impacts on crop growth are important for optimization of crop production. The study involved the assessment of hydro-chemical properties and chemical indices of Owiwi river for irrigation of vegetables from the measured quality parameters and analyzed for important quality indices following standard test procedures. The study revealed that pH of water was acidic in nature resulting in low residual sodium carbonate (RSC) values showing dominance of dissolved CO3, attributed to dissolution of limestone dominant in the study area. The water was regarded as permissible water based on electrical conductivity (EC) and total dissolved solids (TDS), implying non detrimental salinity hazard in the soils. Excessive Na content (> 250 MMg/L) in water reduces the permeability thereby influencing availability of water for the plant usage, obviously associated with low EC and sodium adsorption ratio (SAR) observed in the river water. The excess hardness resulting from high content of calcium and magnesium ions derived from limestone and chalk is undesirable mostly for esthetic reasons like plumbing of irrigation systems. Generally, the water can be classified as good for irrigation of vegetable on the bases of PI, MAR, % Na, SAR and % yield. Keywords: Hydro-chemical, permeability, soil, limestone, yield

Impact of upstream industrial effluents on irrigation water quality, soils and plant in Alakia Area of Ibadan

Knowledge of irrigation water quality is critical to predicting, managing and reducing salt affect on soils. The study assessed the effect of industrial effluents on irrigation water quality, soils and plant tissues in Ibadan, Southwest Nigeria. The degree of pollution was evaluated using Sodium adsorption ratio, pH, cations – Cl and NO3 and 4 heavy metals including Pb, Cu, Cd and Zn using standard procedures. The study established the presence of High pH (pH= 6.65) that caused high alkalinity leading to high SAR of 11.1 which is as a result of calcium and magnesium ions forming insoluble minerals leaving sodium as the dominant ion in solution. Presence of heavy metals in concentration higher than the recommended limits in irrigation water samples analyzed with Cd (0.05 ppm), Cu (0.3 ppm), Pb (0.03 ppm) and Zn (4.0 ppm) in the study location. It was concluded that Eleshin stream and the surrounding ground water is fit for irrigation in relation to sodium hazard, although it is acidic, thus enhancing leaching and corrosive tendencies of the irrigation water. High level of heavy metals in the soil indicated contamination from the effluent from the factories in the area. Plant sampled indicated the presence of higher level of Pb and Cd in the tissues of leaf and roots than that of the reference samples.Keywords: Pollution, discharge, effluent, irrigation, SAR, heavy metal

HYDROMETEOROLOGICAL NETWORK UPGRADE DESIGN FOR OGUN-OSHUN RIVER BASIN

Hydro-meteorological data useful for hydrological monitoring, agricultural production, research and planning in the tropics are grossly inefficient in terms of their practical values as a large number of the stations fall short of the international standard established. This study examined the effectiveness of the existing hydro-meteorological network in Ogun –Oshun river basin in terms of providing useful data for hydrologic processes and agricultural planning. This is with the overall aim of designing an upgrade for the network suitable for providing useful data for agricultural planning and hydrological processes. The design of hydrometeorological network upgrade in Ogun–Oshun river basin was carried following WMO standard for network design. The primary data and field information were obtained from the working files and existing stations of Ogun-Oshun River Basin Development Authority. Results obtained showed that, complete data were scarce and a lot of interpolations had to be done. Thus, important hydrometerological information relevant to agricultural planning and hydrological processes were missing. Also, that the existing spatial distribution of the networks has been found to be highly inadequate in most parts of the river basin. The reliability of hydrometeorological characteristics depends not only on the accuracy of observations, but also on the mathematical background for interpretation of the results. The need to optimize networks, means and methods of observations as well as the procedures and techniques of data processing is also discussed. &nbsp

INTERACTIVE EFFECTS OF PLANTING SEASON, MULCHING AND VARIETY SELECTION ON GROWTH, DEVELOPMENT AND YIELD OF WHITE YAM IN THE TROPICAL WET-AND «¤??DRY CLIMATE OF NIGERIA

The effects of planting season, mulching and variety selection on growth, development and yield of white yam were evaluated in two trials in 2007 and 2008 cropping seasons. Mulching and planting season significantly increased tuber yield and also increased the expression of yield components and vegetative characters. The yield of Efuru and Ise-osi were more than that of Oneyere, particularly on mulched plots during the dry season planting. Early season plantingª¤? significantly (P < 0.05) influenced emergence rate, phenological growth and tuber yield. Irrespective of mulching materials, it was found that mulching significantly (P< 0.05) increased tuber yield by about 6-8 tonnes ha-1 season-1 over the unmulched. Furthermore, grass mulch had tuber yield of about 4-6 tonnes ha-1 season-1 greater than the polythene mulch and the unmulched plots. Growing yam variety that synchronizes the crop growth cycle with effective water availability during the early planting season with proper mulching is therefore recommended.ª¤

An assessment of the effect of industrial pollution on Ibese River, Lagos, Nigeria

This paper deals with pollution aspect of environmental management and monitoring of the river for its sustainable development. The water quality assessment of Ibese River, which is the principal river of the Igbogbo Abayeku Areas of Ikorodu in Lagos, was performed. Assessment was undertaken according to different physical and chemical parameters including biological oxygen demand (BOD), dissolved oxygen (DO), electric conductivity (EC), total dissolved solids (TDS), alkalinity, acidity, total hardness (TH), grease content, major cation and anion, and some heavy metals. Results showed that the river, which was of good water quality at its upstream, in terms of the aforementioned parameters, becomes progressively polluted by the waste materials discharged along its course. A general downstream trend of increase in organic and inorganic pollution was declared. Thus, Ibese River currently faces a number of serious environmental and ecological challenges. Urbanization and industrialization of the watershed at Ibese area in Ikorodu contributed to the water quality deterioration with regional consequences on the aquatic ecosystem and on the health of the downstream’s user groups. This synergetic effect is of concern for the sustainable use of the resources.Key words: Nigeria, Ibese River, water pollution, major cation and anion, heavy metals, water quality deterioration

HUMAN HEALTH AND ENVIRONMENTAL RISK ASSESSMENT OF THE ALAKIA INDUSTRIAL DISTRICT OF IBADAN, SOUTH WEST NIGERIA

A scientific survey was conducted in February 2002 in three communities (Majawe, Osun-Abolowojaiye and Papa Adogba) communities of Alakia Industrial district of Ibadan to determine the extent of the damages caused by the negative impact of the industrial effluent discharges into the Elesin stream and emissions of gaseous pollutants into the atmosphere within the three communities. A socio-economic survey was also carried out to establish the impact(s) on human and livestock populations of the study area. A sample of non-affected areas served as control for comparison. The degree of pollution was established by the determination of the concentrations of the metals including Pb, Ca, N, K, Cd, Fe, Zn, Ca, Cr, Mn, Na, Mg, a specific non metal phosphorus as well as chlorides (Cl-) and Nitrates (N03-). The study established the presence of metals in concentrations higher than the recommended limits in effluent discharges in all the samples in the study area and a clear link between the effluent discharges and pollution with its severe damages in the area

Assessment of the effects of cadmium and lead on pH and cation exchange capacity of soil under different plant canopy in the tropical wet-and dry climate

The effects of heavy metals pollution on agricultural produce can not be over emphasize. To estimate the effect of heavy metal on pH and Cation Exchange Capacities of soil on incubation, relationships between availability of metals in soil after contamination were investigated for a range of soils and metals. Three concentrations (0 mg/kg, 2 mg/kg and 5 mg/kg) of lead and cadmium were added as nitrate solution as single and combine treatments to six soil samples under different plant canopy. The soils-metal were incubated at field capacity for 8 weeks under 250C. The exchangeable bases in soils were determined in IM ammonium acetate (pH 7.0) extract by FAAS and pH by pH meter with a combination electrode. The treatment is arranged in randomised complete design each in triplicates. The pH decreased from 7.02 to 6.70 and 6.63. Cation Exchange Capacities decreased from range of of 6.62 to range of 4.71 and 3.10 C mol kg-1 under single and combined treatments respectively for the six locations. These results enable us to understand natural attenuation of metal contamination and also to assess the risk of soil contamination by determining effects of metals reactions with CEC and pH in 8-weeks incubated soils after artificial contamination.Keywords: heavy metals, Incubation process, pH and CE

Response of soil moisture content to sampling depth and canopy types in a tropical climate, Southwest Nigeria

Soil moisture plays a very important role on vegetation growth and hydrological cycle in tropical wet and dry climates. Response of soil moisture to sampling depth and canopy type in a tropical wet and dry climate, South-West Nigeria was assessed during 2015 meteorological year. The selected canopy types were Cashew plantation(AnacardiumOccidentale) (7°.43¹N, 3°.85¹E), Teak plantation (Tectonagrandis) (7o .66¹N, 3o .84¹E) and Palm tree plantation (Elaeis guineensis) (7o .51¹N,3o .99¹E) all in the Federal University of Agriculture, Abeokuta, Nigeria. Result showed that the moisture values under the Palm tree canopy obtained from the three methods was significantly ( p ≤ 0.05) higher than moisture content from other canopy types, though soil moisture under Cashew had slightly higher moisture readings than those under Palm canopy sometimes. In terms of sampling depth, soil moisture determined by gravimetric method at 10cm depth ranged from 2.92 to 9.48, then at 20cm ranged from 3.41 to 9.46 while at 30cm, it ranged from 3.77 to 9.57. Soil moisture readings obtained using volumetric method at 10cm ranged from 3.62 to 10.30, then at 20cm ranged from 3.79 to 9.87 while it ranged from 4.42 to 11.73 at 30cm depth. The values of soil moisture using TDR method at 10cm depth ranged from 3.31 to 8.46, then at 20cm, it ranged from 3.14 to 9.03 while at 30cm ranged from 3.43 to 9.79. Conclusively, leaves attached to palm tree perhaps maintained their saturated water content longer than leaves attached to shorter trunk such as cashew and teak trees, hence less moisture uptake by palm tree in contrast to cashew and teak trees.Keywords: Soil moisture, Teak plantation, Cashew Plantation, and Palm Plantatio

Sensitivity assessment of maize (Zea mays l.) Cultivars growth parameters to agrometeorological indices in Abeokuta, southwest Nigeria

Growth parameters namely number of leaves, leaf area per plant and plant height were recorded in a field experiment in the late rainy season of 2016 to study the crop growth-weather relationship of four maize cultivars namely TZPB-SR-W, DMR-LSR-Y, ART/98/SW6 and BR/9928. The experimental plots were arranged in a Randomize Complete Block Design replicated three times. The crop growth parameters (number of leaves, plant height  and leaf area) and selected agrometeorological indices namely rainfall, maximum and minimum temperature, relative humidity and sunshine hour were subjected to correlation analysis. The study confirmed that number of leaves for the cultivars used for this research was the most sensitive  parameter to rainfall, minimum temperature and relative humidity fluctuations whereas it was least sensitive to maximum temperature and sunshine hour. Cultivars plant height and leaf area demonstrated highest sensitivity to maximum temperature and sunshine hour, respectively in the study area. The correlations coefficients (r) obtained in the experiment revealed that rainfall, minimum and maximum temperature and sunshine hour were positively correlated with crop growth parameters, but relative humidity was negatively correlated with all selected growth parameters. It was recommended that number of leaves be used as the most critical factor in determining maize cultivars sensitivity to weather vagaries in the study area.Key words: maize, agrometeorological, indices, cultivars, sensitivit

QUALITATIVE AND QUANTITATIVE ASSESSMENT OF RAINWATER HARVESTING FROM ROOFTOP CATCHMENTS: CASE STUDY OF OKE-LANTORO COMMUNITY IN ABEOKUTA, SOUTHWEST NIGERIA

Quantitative and qualitative assessment of Rainwater harvesting system from rooftop runoff from acatchment at Oke-Lantoro Community in Abeokuta, Southwest Nigeria was determined using eightroof designs in respect to slope and six selected roofing sheet materials respectively. The resultshowed that the steeper the roof slope the more the rainwater harvested irrespective of rainfall amountand duration. The roof pattern with a large and steep slope designed with gutter tends to harvest morewater and at a higher rate. Physico-chemical analysis of the harvested water samples gave resultswhich varied from various drinking water quality regulatory standards. Sample from galvanized roofingsheet was influenced by zinc and lead in quantity beyond human consumption level, while the asbestosroofing sheet water sample gave higher calcium and magnesium contents which reflected in thetotal hardness value. Sample from the aluminum roofing sheet gave the best result but it was alsoaffected by the influence of atmospheric dust particles and faecal materials of birds, lizards and othersmall organisms. Considering the results of the physico-chemical tests, the harvested water samplescould be put to other domestic uses, as they cannot be consumed directly