ARID ZONE JOURNAL OF ENGINEERING, TECHNOLOGY AND ENVIRONMENT

1-13

Authors: M S Abubakar, D Ahmad

A dual-purpose disc agrochemical applicator for field crops was developed to boost agricultural mechanization in crop production and also to overcome the safety concern of hazardous spray drift during agrochemical application by the field crop farmers. The dual purpose agrochemical applicator was mounted on a high clearance tractor and tested with respect to the granular fertilizer distribution patterns uniformity/liquid chemical uniformity of droplet sizes in spraying of the agrochemical. Results for NPK granular chemical indicated that, at low (50 kg/ha) and high (150 kg/ha) application rates with 550 rpm disc speed, distribution patterns skewed to the left whereas the distribution pattern at medium (100 kg/ha) application rates was good flattop. Also at high application rate with 1000 rpm disc speed, mean distribution pattern became poor (W-shape). For the liquid chemical herbicide HC 48 amine liquid, the mean values of volume median diameter (VMD) and number median diameter (NMD) were 108 µm and 80 µm at 90 lt/ha application rate at 5000 rpm rotary disc speed, and also 344 and 222 µm at 30 lt/ha application rate with 2000 rpm rotary disc speed. The mean values of coefficient of uniformity for droplet sizes expressed as VMD/NMD found in this study were in the range of 1.35 to 1.55 for HC amine 48 liquid chemical.

25-36

Authors: S Adamu, M V Joseph, M Bukar

Hydrogeological mapping and water chemistry of Gwoza South-West (topographical sheet 114) of the crystalline basement complex at the foot of Mandara Hills in North-Eastern Nigeria was carried out. Rainfall data was collected from the area for a period of 16 years. Water table configuration map and direction of groundwater flow was produced. Chemical analyses and physical parameters of the water was determined using spectrophotometer, flame photometer, ph meter, and electrical conductivity meter. Semi urban water consumption per family per capita per day was determined using 20 households. A total of nine major ions (Ca2+, Na+, K+, Mg2+, Cl-, S042-, N02- and HC03-) were analyzed. Results of the study indicate that the area experiences a moderately average rainfall of about 743mm per annum, depth to water table ranged between 2.6 – 18.8m and 0.1 – 18.2m at the peak of dry season and rainy season respectively and per capital daily water consumption per family, ranged from 9 litres to 76 litres. The values of major ions present in water indicate that it is fit for both human and animal consumption as they fall within WHO (1996) standard. Demand for water is highest in the dry season, when recharge is poorest.

47-52

Authors: H I Ahmad

This paper discusses how extension methods could promote awareness for the needed advancement in agricultural engineering in Nigeria. This could be achieved by revealing the latest operations and giving feedback on farmers/users responses to such technologies. Performance of a number of labour saving devices developed by some of the Nigerian Research institutions and centers requiring commercial adoption are reported.

67-85

Authors: C J Ejieji

An existing solar radiation model developed at Ilorin and found to be more reliable than Angstrom-type and Hargreaves solar radiation equations was used in the FAO Penman-Monteith reference evapotranspiration model (FAOPM) to obtain daily reference crop evapotranspiration (ETo) for a 32-year (1970 to 2001) period. The number of days having all the required input meteorological data was 9335. The sky conditions of the days were classified as clear, partially cloudy or cloudy depending on the cloudiness index i.e. the ratio of diffuse solar radiation to total solar radiation. The ETo values obtained with FAOPM were compared with predictions of three simpler empirical ETo models namely the Hargreaves (HGRV), Jensen and Haise (JHSE) and Blaney-Morin-Nigeria (BMN) models. When the more reliable solar radiation model was used in HGRV and JHSE, their performances were better than when the solar radiation equation of Hargreaves was used. Generally the three simpler models overpredicted ETo. The bias, root mean square difference (RSMD) and absolute error of prediction deteriorated with sky cloudiness when the solar radiation equation of Hargreaves was used. Linear regression equations with zero intercepts were developed for the estimation of FAOPM predictions from those of the simpler ETo models. The regression equations relating the predictions of FAOPM to those of HGRV generally yielded the highest coefficients of determination and the lowest standard errors of regression. The predictions of HGRV were also the closest to the corresponding FAOPM predictions under the various sky conditions. Based on the outcome of the regression analysis and the ease of application of HGRV, the FAOPM-versus-HGRV regression equations were recommended for the estimation of FAOPM predictions of daily ETo when the use of FAOPM is necessary but not feasible because of incomplete input data.

95-104

Authors: U M Abubakar, I Nkama

he moisture sorption behavior (adsorption and desorption) of guna seeds (shelled and unshelled) was observed under water activity range of 0.147 to 0.981 and temperatures of 10oC, 30oC and 50oC, respectively. The sorption data were subjected to spreadsheet computer plots (Microsoft excel) of equilibrium moisture content versus water activity. Best fit curves were observed to be polynomials of the third order with correlation coefficients (for unshelled seeds) ranging from 0.9854 to 0.9434 for adsorption and 0.9778 to 0.9749 for desorption and percentage root mean square of error (%RMS) ranged from 0.63 to 1.35 and 0.58 to 0.65 for adsorption and desorption, respectively. The curves for the shelled seeds showed correlation coefficients that ranged from 0.9812 to 0.8986 for adsorption and 0.9706 to 0.9065 for desorption, with corresponding %RMS of 0.66 to 2.15 (adsorption) and 0.76 to 1.41 (desorption). In all cases, the correlation coefficient decreased with increasing temperature while %RMS increased with temperature.

115-123

Authors: M Hassan, M M Uba, A A Zarma

Geoelectrical depth soundings were conducted on the same area on the Bama Ridge at different times of the year, covering over three seasons. The surveys were conducted at the beginning of the rainy season and repeated at the end of it. These times corresponds to when the river bed is almost empty of water (June) and when the Ngada River is still flowing and it is at its highest stage (October) respectively. The interpreted results of the study show that the shallow aquifer of the Bama Ridge is in hydraulic connection with the Ngada River. The apparent resistivity curves also indicated that Vertical Electric Sounding (VES) could be used as a preliminary technique to explore possible river-aquifer interaction phenomena in a hydrologic system.

133-138

Authors: M B Oumarou, G M Ngala, F A Oluwole

The paper treats the design of a municipal solid waste incinerator suited to the semiarid regions with northern Nigeria and Niger Republic in West Africa as the study area. Proximate and ultimate analyses results from the solid waste were used as basis for calculations, using standard formulas and correlations. The calorific value of the solid waste samples in the study area is not high enough to sustain an incineration process and it ranges from 5.024 MJ/kg to 5.867 MJ/kg. For these types of low calorific value fuels, the parallel flow concept was found to be the appropriate type of incinerator. The solid waste to be fed in the incinerator needs to be mixed with 50% of supplementary fuel in the form of readily available bagasse to make it up to the required lower calorific value. Major characteristics of the designed municipal solid waste incinerator were: total volume of incinerator chamber: 82.5 m3, length of the incinerator bed: 11m; width of the incinerator bed: 3m and height of the incinerator chamber: 2.5 m, while the suitable adiabatic flame temperature was found to be 1,587 K.