Department of Agricultural and Environmental Engineering
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- ItemOpen AccessAgricultural Mechanisation in Nigeria: the Prospects and Promises(Obafemi Awolowo University Press, 1977-10-20) Makanjuola, G. A.The application of technological innovations to the solution of problems is perhaps the single most important factor responsible for human progress. This inaugural lecture addressed: importance and role of agricultural mechanisation as a vehicle for agricultural production; problems faced by Agricultural Engineering as a profession; present state of mechanisation in Nigerian agriculture; type and level of mechanisation appropriate to our farming system; contribution of the University of Ife to agricultural mechanization in Nigeria; and challenges of ensuring that our future mechanisation programmes are meaningful and fruitful.
- ItemOpen AccessTreating Rural Water without Introducing Harmful Substances(Faculty of Agriculture, University of Ife, 1980) Ogedengbe, O.The coliform count on the stream water studied was high. The water is a direct source of drinking water to some rural communities. A previous study established that about 100 ppm of chlorine in the form of chlorox was sufficient to bring: the coliform Most Probable Number (MPN) from about 11,000 per l00ml down to within allowable standard of one per l00ml of water sample. There is some concern that turbid water contains organic matter which when chlorinated could give rise to formation of chloroform and possibly other chlorine-based compounds of the trihalomethane family which conceivably could be carcinogenic. This prompted design and construction of a simple system of turbidity removal and chlorination. With this system the required chlorine dosage even went down to about -50 ppm.
- ItemOpen AccessStudies on the Effect of Conditioning Processes on the Field Drying time of Forages(Faculty of Agriculture, University of Ife, 1983) Ajibola, O. O.The effects of conditioning processes, underlying layer and weather factors on field drying rate of alfalfa were investigated. Drying of chopped, macerated and dewatered alfalfa was affected progressively by the intensity of the change in physical characteristics and inversely by the rate of moisture transfer from the underlying surface. The depressing effect on the drying rate of rolling the macerated and dewatered samples into sheets approximately 6mm thick, was more noticeable on a wetter underlying surface.
- ItemOpen AccessInfluence of Speed and Land Slope on Uniformity of Distribution and Metering of Cowpea Seeds(Faculty of Agriculture, University of Ife, 1985) Saqib, G. S.; Segun, O. O.Investigations were carried out to evaluate the effects of field slope and forward speed on the metering uniformity of the grain drills for planting cowpea. The study was conducted in the laboratory using a John Decre model 8250 grain drill while the field slopes and forward speeds were simulated. The field slopes were varied from zero to 12.5 degrees, while the forward speeds were varied from 3 to 6 km/h. The metering uniformity of the drill was measured in terms of coefficient of variation in the seeds metered and delivered by various seed delivery tubes across the width of the machine. The actual seeding rate delivered by the - grain drill under various field and operating conditions was also determined. Results indicated that the field slope and forward speed had significant effect (p <0.01) on the metering uniformity and seeding rate. There was decrease in the metering uniformity and the seeding rate with an increase in the field slope in the range tested. Similarly, an increase in forward speed resulted in poorer metering uniformity and lesser seeding rate at the field slopes ranging from zero to 12.5 degrees. The interaction between the field slope and the forward speed appeared to be non-significant. Statistical models were developed to predict the metering uniformity and the seeding rate delivered by a grain drill operating at various forward speeds for planting cowpea seeds in sloping lands of Oyo State of Nigeria.
- ItemOpen AccessDesorption Isotherms for Plantain at Several Temperatures(Faculty of Agriculture, University of Ife, 1985) Ajibola, O. O.Moisture equilibrium data for desorption of water from ripe and unripe plantain were obtained at 40°, 50o, 60° and 70o over a range of relative humidities from 10 to 90 percent, using a static gravimetric method. Rite plantain exhibited higher equilibrium moisture content (EMC) than unripe plantain under the same conditions. A non-linear least squares regression programme was used to fit 5 desorption isotherm models to the experimental data and the parameters of the models evaluated. Using the modified Halsey model, the minimum standard error of estimates of the EMC was 1.9% for ripe and 1.4% for unripe plantain.
- ItemOpen AccessSterilization and Mechanical Digestion of Oil Palm Fruits [Elaies Guinnensis, Jacqin].(Obafemi Awolowo University, 1987) Babatunde, Oludare Oni; Makanjuola, G.A.; Ige, M.T.Investigations were carried out on the effects of sterilization on fruit recovery during palm oil extraction and the rupturing strength of the fruit mesocarp. Equations were developed for predicting power requirements of both the vertical and horizontal palm fruit digesters and the effects of both digesters in facilitating palm oil extraction were compared. Fruit stripping was carried out after sterilization of freshly harvested fruit bunches and spikelets. The sterilization of the fruit samples was carried out in saturated steam at 100°C and 130°C for 15 to 120 minutes. The crushing strength of the fruit mesocarp was determined as a function of sterilization time and steam temperatures of 100°C and 130°C. Regression analysis was carried out on data collected from measurements of power consumption for the development of equations for the operation of the digesters. The effect of the digesters in facilitating palm oil extraction was compared in a 25 factorial design. The factors were: (1) Equipment (2) Orientation (3) Speed of operation (4) Content of the digester and (5)Sterilization condition. The results of the experiments show that: (1) Palm fruit recovery is improved by processing spikelets in non-pressurized sterilizers and by processing fresh fruit bunches at 130°C in saturated steam. (2) The crushing strength of palm fruit mesocarp decreases with sterilization time. The residual crushing strength is about 460 kN/m2 and 580 kN/m2 after sterilization respectively for 60 minutes at 130°C and 90 minutes at 100°C of saturated steam. (3) Modeling equations were developed for design and operation of both types of digesters. The equations relate the power requirement to the mass of fruit charge, crushing strength of the fruit, diameter of cylinder and shaft speed of the digesters. (4) Vertical orientation of the digesters and sterilization of the palm fruit at 130°C of saturated steam significantly improves palm oil extraction.
- ItemOpen AccessEffect of Rainwater Harvesting Technology on Cowpea Yield in the Savannah Belt of Nigeria(2015-04-17) Balogun, James AdebayoThis study investigated the effects of two rainwater harvesting (RWH) technologies (micro) and macro-catchments) on cowpea yield in the savannah belt of Nigeria with a view to identifying the better technology that could mitigate against adverse effects of erratic rainfall. The study was carried out in Afikuyomi village (between latitude 7° 45' N and longitude 4° 10' E) 10km north of Iwo town (Osun state) in the derived savannah belt of Nigeria. In the micro catchments RWH, both the runoff producing area (RPA) and runoff receiving area (RRA) lie typically within a single farmland while in the macro catchment system, the two areas (RPA) and RRA) do not lie within a single farmland. The micro catchment plot has a slope of 2° and four treatments: RWH, Semi-circular bunds (SCB), Semi-circular bunds with RWH (SCB+RWH) and the control plot. The experimental layout was completely randomized with three replicates of each treatment. Each of the four sub plots measured 7m x 5m. The macro catchment plot was made up of four treatments: Double soil manipulation (DSM) with RWH (DSM+RWH), Single soil manipulation (SSM) with RWH (SSM+RWH), Zero tillage (ZT) with RWH (ZT+RWH) and the control plot laid out in complete randomized design with two replicates. Each of the four sub-plots measured 5m x 5m. Plant and soil parameters were measured fortnightly during the growing period. At maturity, yield and its components were determined. The results showed that in the micro catchment plot, the average soil moisture content were 10.95%, 10.08%, 8.90% and 7.69% in the SCB+RWH, RWH, SCB and control treatments respectively at 0-15cm,15-30cm and 30-45cm depths. The highest crop yield of 0.47t/ha and 1.55/ha dry matter were obtained for the SCB+RWH treatment compared to 0.31t/ha and 1.18t/ha for the control. Furthermore, the SCB treatment had the highest water use efficiency value of 7.7okg/hacm-1 compared with 6.09kg/hacm for the RWH p<0.05). In the macro plot, DSM+RWH gave the least soil penetration resistance of 6.8N and bulk density of 1.50g/cm3 compared with 30.75N and 1.61 g/cm3 for the control treatment. Also, the highest crop yield of 1.84t/ha, 3.3t/ha dry matter and 26.52kg/ha cm-1 water use efficiency (P<0.05) were obtained for DSM+RWH compared with 0.78t/ha and 2.64t/ha for the control and 13.0kg/hacm-1 water use efficiency for the ZT+RWH treatment. The results showed that cowpea yield can be increased using either micro-catchment RWH with Semi-circular bunds (RWH+SCB) or Macro catchment RWH with double soil manipulation (RWH+DSM).
- ItemOpen AccessOptimization of Thermal Comfort in a Naturally Ventilated Livestock Building(2015-04-29) Ogunjimi, Lawrence Abiodun OgunsolaThis work investigated the effect of building vent and orientation on the thermal comfort of rabbits under a naturally ventilated livestock building. This was with a view to optimizing the productivity of the animals. Mathematical equations were used to estimate heat and moisture production by the animals, airflow rate and the Temperature-Humidity Index (THI) of the building. The experiment was conducted using two model buildings oriented at 45° and 90° to the northeast wind. Two inlet vents of 30% and 50% on the windward side and an outlet opening of 20% on the leeward side of the model buildings were used. The experiment was carried out using a 3 x 2 x 2 factorial arrangement with two replicates. The factors were inlet opening, orientation and sex of the animal. A rabbitry without wall on all sides was used as the control building. Data on temperature and relative humidity within and outside the buildings were collected twice daily (7.00 a.m. and 1.00 p.m) and used to calculate the THI. Rabbit weight gain and feed consumption were collected while feed utilization efficiency was calculated on weekly basis. Physiological parameters of pulse rate, rectal temperature and respiration rate were also collected twice a week. The data were analysed using inferential statistics. The results showed that the amount of building opening (difference in the height to length) and orientation significantly (P < 0.01) affected the thermal comfort level of a livestock building. The average THI values were 33.16°C oC, 34.80 °C and 34.33 °C respectively for 50%, 30% and the control (100% opening) buildings, respectively. The building orientation also had significant effect (P < 0.01) on the productivity characteristics of the rabbits. Also, THI were 33.35 °C and 34.61 °C for the 90° and 45° building orientations, respectively. This was attributed to the variations in heat and moisture removal from the buildings. The weight gain and feed efficiency of rabbits in the 90° orientation building were respectively 7.53 g and 0.03 higher than those for 45° orientation building. However, the pulse rate, rectal temperature and respiration rate were 6.95 bpm, 0.84 °C and 6.54 rpm lower in the 90° orientation building than the 45° orientation respectively. Female rabbits also responded better than male rabbits (P < 0.01) with average of 0.61 g and 0.01 higher values of weight gain and feed efficiency, respectively. In conclusion, the study showed that both building orientation with respect to the direction of the prevailing wind and size of ventilating opening affected the Thermal Comfort Indicator (THI).The combination of 50% opening and 90° orientation of the buildings gave the best THI value of 32.49 °C. Under all conditions, the female rabbits responded better than the male in the production characteristics.
- ItemOpen AccessDevelopment of a Composting Chamber for the Reduction of Nitrogen Loss in Poultry Litter(2015-04-30) Ogunwande, Gbolabo AbidemiThe study was undertaken to develop a chicken litter composting chamber and investigate the effects of turning frequency (TF) and carbon to nitrogen (C:N) ratio on the loss of nitrogen (N) in chicken litter piles. This was with a view to producing good quality compost. The experimental set up was a 3 X 3 factorial design with turning frequencies at every 2, 4 and 6 days, and C:N ratios at 20:1, 25:1 and 30:1. The organic materials were composted in a chamber of size 1.2 m x 1.2 m square base and a height of 0.3 m. Each treatment was replicated thrice and turned manually using a hand shovel. During the composting process, the moisture content in the piles was periodically replenished to 55%. The temperature, moisture content (MC), pH, ash, total nitrogen (N), total carbon (C) and C:N ratio of the chicken litter were periodically monitored. The total phosphorus (P) and total potassium (K) contents were determined at the end of composting. Cumulative losses of N and C were quantified to determine actual losses during composting. The data obtained were analyzed using inferential statistics. The results showed that the developed chamber was effective for composting as indicated by the attainment of thermophilic temperatures during the 87 days of composting. It also showed that 'TF and C:N ratio had significant effect (p < 0.05) on moisture loss (F2, 2 4 = 55.24 and 44.32), C (F2, 24 = 68.51 and 35.86), N (F2, 24 = 90.23 and 99.57) and C:N ratio (F2, 24 = 215.35 and 184.94) while temperature was only affected by the C:N ratio (F2, 24 = 7.57, p < 0.05) and pH affected by the T F ( F 2 , 2 4 = 4.63, p < 0.05). Losses of N, which were attributed to volatilization of ammonia (NH3), were highest during the period when the litter temperatures were above 33 °C and the pH values above 7.7. The losses of C were attributed to organic matter (OM) degradation. At the end of composting, TF of 4 days with C:N ratio 25:1 (T4R25) gave the minimum N loss (45.77% of the initial N) resulting in the lowest C:N ratio (24:1) as required of good quality compost while TF of 6 days with C:N ratio 20:1 (T6R20) gave the minimum C loss (41.40% of the initial C). In conclusion, the study showed that good quality compost could be produced using the chamber developed with 4 days TF and initial C:N ratio of 25:1.
- ItemOpen AccessEffect of Irrigation Systems on Yield and Water Use of Okra and Amaranthus Hybridus(2015-05-08) Olanusi, Olaniran AbdulThe study investigated the growth and yield of okra and Amaranthus hybridus under four irrigation systems, in order to determine the most economical system in terms of water use efficiency, cost inputs, and optimal crop yield. Four irrigation systems, namely, sprinkler, drip, basin and furrow systems were designed and established for the study. The research was carried out using a completely randomised block design of 4 treatments and 3 replicates giving a total of 12 sub-plots with each sub-plot measured 10 m x 8 m. Irrigations were carried out when the available water at the crop root zone depleted to 50% of the soil moisture at field capacity. The soil moisture was monitored using the gravimetric sampling method. Pan evaporation method and the Penman equation were used to determine evapotranspiration. The plant height, leaf counts, leaf area, leaf area index and yield components were measured at different stages of plant growth. The data obtained were subjected to descriptive and inferential statistical analysis to compare crop performance under the different irrigation systems. Engineering economic analysis of growing okra and Amaranthus hybridus under the different irrigation systems was also carried out. The results indicated that okra and Amaranthus hybridus responded well to drip irrigation system when compared to other systems. Drip system gave the largest leaf area of 56.23 cm2 at the end of the third week of the planting. The least leaf area was observed in Amaranthus hybridus grown under the furrow irrigation system. The difference in leaf area of Amaranthus hybridus grown under all the irrigation systems was significant (P<0.05, F=163.38). The highest yield (1875 kg/ha) of Amaranthus hybridus was obtained under the drip irrigation system, while the least (1250 kg/ha) was obtained under furrow irrigation system. A similar trend was obtained for okra, with the highest and least yield of 1551 kg/ha and 972 kg/ha for drip and furrow systems. respectively. The total irrigation water applied to Amaranthus hybridus under the sprinkler, drip, basin and furrow systems was 53, 49, 91 and 74 mm, and these gave water use efficiencies of 32.5, 38.0, 15.2 and 16.9 kg/mm, respectively. The benefit-cost ratios were 0.6, 1.0, 0.7 and 0.7, for sprinkler, drip, basin, and furrow irrigation systems, respectively. On okra plots, the water use efficiency of total irrigation values applied for sprinkler, drip, basin and furrow systems were 3.9, 5.7, 2.4 and 2.2 kg/mm, respectively. The benefit-cost ratios were calculated to be 0.5, 1.1 , 0.8 and 0.7 for sprinkler,'drip. basin and furrow irrigation systems in that order. The cost recovery factor ratio was 4.2, the annual energy cost factor 1.0008, and the annual depreciation cost was N215.08. The study concluded that drip irrigation system was the best in terms of benefit – cost ratio, yield and water use efficiency for both crops.
- ItemOpen AccessSimulating Soil and Groundwater Contamination by Copper and Manganese from Agricultural Fungicides(2015-05-14) Osunbitan, Jimmy AkinfemiThis work developed predictive models that simulated the transportation of copper and manganese from agricultural fungicides through the soil profile as well as the adsorption of the metals to the soil particles. The experiment was conducted in two stages and these stages were Batch Equilibrium Test (BET) and Soil leaching experiment. The BET was conducted as 2 x 4 x 6 factorial experiment. The variables were soil types (Egbeda and Apomu), pH and fungicide concentration. The leaching experiment was conducted as 2 x 3 factorial experiments. The variables were soil type (Egbeda and Apomu) and fungicide concentration. For Batch Equilibrium test, air-dried soil sample of about 1 g was equilibrated with 10 ml solution containing the desired concentrations of the fungicide in a centrifuge. After equilibration and centrifugation, the supernatant were analysed for copper and manganese using Atomic Absorption Spectrophotometer (AAS). Absorption was then estimated from the decrease in the concentration of the metals in the fungicide in the liquid phase after equilibration. For the column leaching experiment, soil columns were wetted at the rate of about 5 mm/h for 1 day. After saturation, the fungicides were applied and the columns kept completely saturated with water by maintaining ponding through continuous application of de – ionized water at a rate of about 10 mm/hr for the duration of the experiment. Leachate samples were collected every 6 hours for 7 days and the leachate analysed for copper and manganese using AAS. Data were analysed using descriptive and inferential statistics. Data from the BET and column leaching experiment were used to modify and validate relevant models. The result of the BET showed that the equilibrium metal concentrations in the soil solution increased significantly with increasing metal concentration in the solution (P < 0.05). The solution pH was significant (P <0.05) in its effect on the amount of metals adsorbed into the soil and the two soils were also significantly different (P < 0.05) in their adsorption capacity. The adsorbed metal increased with increase in solution pH and metal concentration with the maximum adsorption capacities at pH 6 and metal concentrations of 4.50 g/l and 1.44 g/l for Copper and Manganese respectively. Adsorption of copper into Egbeda and Apomu soils was best explained with Langmuir equation with r2 = 0.99 and 0.97 respectively while Freudlich equation was the best model that explained the adsorption of manganese to the two soil types (r2 = 0.95). The results of the leachate experiment showed that the factors considered were all significant (P < 0.05) in their effects on the concentration of the metals in the leachate. Furthermore, the result showed that the developed model was able to simulate the relative metal concentrations in the leachate. The r2 ranges for Copper and Manganese were 0.95 to 0.99 and 0.71 to 0.98 respectively. The estimated values of the solute velocity and dispersion coefficient were also within the 95% Confidence Interval of the breakthrough curves estimates. The study concluded that the developed model predicted well the fate of the metals in the soil - water environment when fungicides are applied to the soil.