Papers by Obafemi Olubanjo
Assessment of climate change impacts on the hydrology of the Peruvian Amazon-Andes basin
Hydrological Processes, 2011
ABSTRACT In this article, we propose an investigation of the modifications of the hydrological re... more ABSTRACT In this article, we propose an investigation of the modifications of the hydrological response of two Peruvian Amazonas–Andes basins in relationship with the modifications of the precipitation and evapotranspiration rates inferred by the IPCC. These two basins integrate around 10% of the total area of the Amazonian basin. These estimations are based on the application of two monthly hydrological models, GR2M and MWB3, and the climatic projections come from BCM2, CSMK3 and MIHR models for A1B and B1 emission scenarios (SCE A1B and SCE B1). Projections are approximated by two simple scenarios (anomalies and horizon) and annual rainfall rates, evapotranspiration rates and discharge were estimated for the 2020s (2008–2040), 2050s (2041–2070) and 2080s (2071–2099). Annual discharge shows increasing trend over Requena basin (Ucayali river), Puerto Inca basin (Pachitea river), Tambo basin (Tambo river) and Mejorada basin (Mantaro river) while discharge shows decreasing trend over the Chazuta basin (Huallaga river), the Maldonadillo basin (Urubamba river) and the Pisac basin (Vilcanota river). Monthly discharge at the outlet of Puerto Inca, Tambo and Mejorada basins shows increasing trends for all seasons. Trends to decrease are estimated in autumn discharge over the Requena basin and spring discharge over Pisac basin as well as summer and autumn discharges over both the Chazuta and the Maldonadillo basins. Copyright © 2011 John Wiley & Sons, Ltd.
Evaluation of Irrigation Water Quality from Major Water Sources in Ondo and Osun States, Nigeria
Journal of experimental agriculture international, Jun 23, 2018
Journal of Agricultural and Engineering and Technology (JAET)
This study investigates the different soil fertility managements and tillage practices on soil ph... more This study investigates the different soil fertility managements and tillage practices on soil physico-chemical and hydraulic properties as well as the growth, varietal yield performance and water use efficiency of Cowpea (Vigna unguiculata (L.) Walp) varieties in tropical Alfisol in Akure Southwestern Nigeria. The experimental design was as a 2 × 2 × 3 factorial combinations comprising of two levels of cowpea varieties, two levels of tillage treatments and three levels of soil fertility management measures to form a total of 12 treatments, replicated 3 times forming a total of 36 plots. Soil amendments significantly improved the physical and chemical properties of the soil compared with the control. Tillage systems have significant effect (p ≤ 0.001) on Potassium (K) with Traditional tillage (TT) having significantly higher K than No-tillage (NT) system. Highest values in most of the growth parameters were observed in plots treated with Nitrogen Phosphorus Potassium (NPK) fertilizer. Fertilizer (NPK) and manure (organic) applications significantly (p ≤ 0.05) increased crop yield parameters (number of pods per plant, number of seeds per pod, 100seed weight, pod yield and seed yield). The increase in yield parameters as a result of soil amendment is due to the increase in soil fertility observed from the application of poultry manure and NPK fertilizer. The Field Water Use Efficiency (FWUE) of the two varieties was significantly different, and was also significantly influenced by amendment types. Growth, yield, and FWUE of both varieties increased as a result of improved soil physico-chemical (nutrient availability) and hydraulic properties, as well as increased water use of cowpea plants due to the application of poultry manure. Improvement in the management of land resource for sustainable agricultural use would be one of the most useful strategies that could help to increase agricultural productivity and address food security.
International Journal of Engineering and Modern Technology (IJEMT), 2024
Charcoal production is the process of converting wood or other organic material into charcoal thr... more Charcoal production is the process of converting wood or other organic material into charcoal through the application of heat in absence of oxygen. To investigate the effect of charcoal production on soil properties, soil samples from ten soil sampling points were collected at a depth of 0-15 cm at kiln site and adjacent fields (control). The study revealed that the earth kiln method used by charcoal producers has significantly increased pH of soil (< 5.5) to be acidic. Soil organic matter (OM) and organic carbon (OC) was high at most areas of the site (74.2%), while others fall within the ranges of low to medium. Available macronutrient status for Nitrogen (0.06 %-0.23 %) falls within moderate to high ranges while (P, K, Ca, Mg) falls within moderate to high ranges (0.22 Cmol/kg-7.15 Cmol/kg), having few points low in these contents. The availability of micronutrients was highly variable. Zinc (Zn) were moderate at almost all areas, iron (Fe) was low (41.9%), while copper (Cu) was moderate and high respectively across the site (0.18 mg/kg-0.31 mg/kg). Base on this result it was understood that the coarsening particles resulting from charcoal production has implication for nutrient availability resulting in less nutrients available for crops use. Therefore, the study suggest for an improved method of charcoal production should be used, regulation of indiscriminate felling of trees and woodlot should be established in areas of charcoal production.
Applied Research Journal of Environmental Engineering
In recent times and across the globe, the concept of climate has gained much relevance because of... more In recent times and across the globe, the concept of climate has gained much relevance because of its dynamic and complex nature and the significant influence it has on various aspects of the environment, including the increasing threat of global climate change. This study focuses on the assessment of climatic variation in Ilorin based on the variations in rainfall and temperature within the period 1980-2015. Time Series Analysis was used to determine the trend of rainfall and temperature within the period 1980-2015. The 5-Year Moving Average was used to smoothen the time series and to eliminate unwanted fluctuations. Linear Regression was used to estimate the value of variable Y (total rainfall or average minimum temperature), corresponding to a given value of variable X (time), while MAKESEN software was used to determine the temporal trend of rainfall indices within the study period. Furthermore, the study focused on the spatial variations of total rainfall and average minimum te...
Theoretical and Applied Climatology
ABSTRACT
This paper describes the use of weighing-type mini-lysimeters to measure the crop water... more ABSTRACT
This paper describes the use of weighing-type mini-lysimeters to measure the crop water demand of rain-fed cucumber and okra. The mini-lysimeters were constructed from readily available materials like vehicle tubes filled with water and plastic tanks for the lysimeter tank, which were then connected to a weighing system using manometer glass tubes. The consumptive use of okra was between 2.97 mm/day to 26.79 mm/day with a seasonal average of 7.35 mm/day. The water uses of the cucumber crop also varied from 1.13 mm/day to 28.96 mm/day with a seasonal average of 5.79 mm/day. The okra and cucumber crops used 419.06 mm and 364.81 mm of water each season, representing 52.84% and 57.48% of the seasonal rainfall, respectively. Estimating crop water demand and other aspects of the soil water balance under rain-fed conditions is made easier by the use of a mini-lysimeter.
Keywords: Evapotranspiration; Rainfall; Drainage; Runoff depths; Lysimeters.
Iconic Research and Engineering Journals
Improper waste disposal practices have raised concerns about potential environmental hazards. It ... more Improper waste disposal practices have raised concerns about potential environmental hazards. It is fueled by rapid urbanization and population growth. This study focuses on assessing the changes in the physiochemical properties of the soil in proximity to a municipal dumpsite and evaluating the extent of groundwater contamination. A total of ten soil samples were collected, three at varying distances around three different dumpsites, and groundwater samples were taken from three wells at different landfills. The soil parameters determined include pH, organic carbon content, organic matter content, nitrogen, potassium, phosphorus, sodium, calcium, magnesium, copper, iron, chromium and zinc. The water parameters determined include pH, calcium, copper, iron, nitrate, hardness, sulphate, total dissolved solids, dissolved oxygen, turbidity, chloride and zinc. The study found that the soils at the dumpsite were slightly acidic, with a pH range of 5.20 to 6.16. The heavy metals (Cu, Cr, Fe, Zn) were in the same range as the control site. The organic carbon and organic matter content were mostly in the same range as the control site, with ranges 0.28 % to 2.99 % and 0.48 % to 5.12 % respectively. The macro-nutrient concentrations were also in the same range as the control site. The water samples tested had a slightly acidic pH range of 5.94 to 6.68, with minimal heavy metal presence. Calcium levels were found ranging from 55.06 mg/l to 152.88 mg/l. Nitrate was found ranging from 12.45 mg/l to 2600.00 mg/l exceeding the NSDWQ and WHO standard. Other parameters like total dissolved solids, hardness, chloride, turbidity, and sulphate were below the NSDWQ and WHO limits. Statistical analyses indicated significant differences at 95% level. Treatment of water before use and use of alternative water sources as well as landfill redesigning are suggested.
Sustainable Agriculture Research, 2022
Hydroponics is a new branch and aspect of food crop growing that in recent years made its mark in... more Hydroponics is a new branch and aspect of food crop growing that in recent years made its mark in developing country such as Nigeria. Although, its adoption has not been too encouraging. This research work aimed at developing a drip technique system of hydroponics in determination of the agronomic parameters of cucumber by comparing the yield, water and nutrient efficiency, its consumptive use and proximate and mineral composition of cucumber. The experiment was carried out in a complete randomized design with three treatments; organic substrate (coconut coir), inorganic substrate (styrofoam) and soil. These treatments were replicated five times. The vegetative growth (agronomic parameters), yield, water and nutrient, proximate and mineral composition were measured. The result showed the consumptive use as 0.0044 m3 per day and 0.3212 m3 as the water and nutrient use efficiency. The result also showed that organic substrate gave the highest mean plant height of 736.66 mm, highest me...
Journal of Digital Food, Energy & Water Systems, 2021
This study aims to improve the understanding of the impact changes being experienced in our clima... more This study aims to improve the understanding of the impact changes being experienced in our climate system will have on the level of crop productivity in the immediate period as well as in the nearest future. Nigeria was used as a case study and an observed climatic dataset was obtained and used alongside collected 20 year cassava, rice and soybean yield data to develop models that were applied to estimate future crop yield. Four statistically downscaled and bias-corrected Global Climate Models (GCMs): NOAA, MIROC5, ICHEC, and NCC performed simulations for the period 1985–2100 under the Representative Concentration Pathway RCP8.5. These were used to predict how the yields of cassava, rice and soybean will be in the years 2020-2050 and 2070-2100 for the 36 states in Nigeria and the FCT. 89 Empirical models were developed to estimate the yields of the three crops earlier mentioned across Nigeria with their coefficient of determination (R2) ranging between 15% - 99%. The result showed ...
European Journal of Agriculture and Food Sciences, 2021
An agriculture system known as hydroponic is a modern-day agricultural practice. Since it does no... more An agriculture system known as hydroponic is a modern-day agricultural practice. Since it does not require soil for crops to grow, it is therefore referring to as soilless farming. It is a good alternative for producing healthy crops and vegetables, free from soil-borne pathogens as it is not growing on soil. Does every crop perform well on hydroponic systems? To know this answer, we carried out this experiment to test the performance of jute mallow in a newly developed greenhouse and root dipping hydroponic systems developed at the Department of Agricultural and Environmental Engineering experimental farm at Oba-nla, Federal University of Technology, Akure, Nigeria. To compare its growth, we planted them on raised soil beds even though plants perform better on raised soil beds above on the ground soil. To compare the growth parameter of all plants we collected data of plant height, stem girth, and leaf number. We also measured the yield for each crop at the end of the experiment. T...
The quantity and generation rate of solid wastes in Nigeria is increasing over the years with lac... more The quantity and generation rate of solid wastes in Nigeria is increasing over the years with lack of efficient and modern technology for its management. The field research was approached through extensive literature search, administering of questionnaire, interview and personal observation by selecting seven daily markets in Ilesha for data collection. The study was carried out to examine the effects of improper handling and disposal of domestic wastes on the lives and health conditions of people of Ilesha and its environ. A simple random sampling was used to select the market. The selected markets are Idasa, Adeti, Idi-Ose, Oja-Oba, Korede, Irojo and Sabo. Out of the total sample size of 300, 60% of them were females and while40% were males. The study sample randomly included 49% of students leaving in the study communities, 25% of the respondents were operating private businesses while 17% were in the civil service category. However, 9% of the respondents included in the study sa...
The hydroponic techniques of growing vegetables have increased tremendously in developed countrie... more The hydroponic techniques of growing vegetables have increased tremendously in developed countries over years while it is still new in developing countries such as Nigeria and other African countries. The knowledge of this methods and choice of suitable substrates for growing hydroponically are not known to many. More also, the behaviour of the crops when organic growing media are used as support system has not been established in Nigeria. African spinach plants were grown hydroponically using sawdust and rice husk as support system. This research determines the effect of substrates on optimum growth, yield and nutrient composition of African spinach plant so as to form an effective basis for selection of substrates to be used as plant support in soilless farming methods. The experiment was carried out in a completely randomized design with three treatments (sawdust, rice husks and soil) and replicated three times. The agronomic and physiological responses of this crop using differe...
International Journal of Water Resources and Environmental Engineering, 2018
Climate change influences crop yield vis-à-vis crop production to a greater extent in countries l... more Climate change influences crop yield vis-à-vis crop production to a greater extent in countries like Nigeria where agriculture depends largely on natural circumstances. This study assesses the effect of observed climatic variables (rainfall, temperature and relative humidity) on yield of major crops which are divided into two groups, tuber crops (cassava and yam) and fruits (pepper and tomatoes) in Ondo State Nigeria. Crop yield and climatic data were obtained from Ondo State Agricultural Development Project (ADP), Ondo State for a period of nineteen years (1996-2014). These data were analyzed using SPSS 16.0 and Microsoft Excel in order to evaluate the effect of climate on the yield on reference crops in Ondo State, Nigeria. Multiple regression, trend analysis, and ANOVA techniques were used to analyze the data. The study showed that the rainfall range for the nineteen years was 1013.08 mm; temperature range was 5.14°C and relative humidity range was 11.55%. Variations in rainfall, temperature and relative humidity were found to have effects on cassava, yam, pepper and tomatoes yield by 20.7, 18.6, 26.8 and 15.5%, respectively. It was then recommended among other things that the extension agents should work with the Nigeria meteorological agency to advice farmers in the State in order to use cropping calendar in accordance with the weather forecast since temperature, rainfall and relative humidity had little effect on cassava, yam, pepper and tomatoes yield in Ondo State.
International Journal of Clean Coal and Energy, 2019
The overdependence on crude oil in African countries warrants the need for alternative sources of... more The overdependence on crude oil in African countries warrants the need for alternative sources of energy. A 56-litre-capacity biogas digester was designed, fabricated and evaluated. Investigations were made into the production of biogas from the mixture of cow dung, swine dung and poultry dropping. Standard equations and models were used in the design of the components of the manually operated digester. The digester temperature, ambient temperature and pH were monitored during the experiment. The proximate analysis showed that volatile solid, total solid and moisture content for the mixed substrates at the initial stage were: 64.7%, 83.5% and 13.5% respectively. Similarly, at the digestion stage, the volatile solid, total solid and moisture content were: 54.1%, 22.6% and 74.4% respectively. Advancement of decomposition leads to gradual increasing pH value from 7.2 to 7.4, which indicates the stability of organic matter. The moisture content on a wet basis was initially 13.5%. This value latter increased to 74.4%. On the average, 15 kg of mixed substrates with 25 litres of impure water produced biogas within 25 days of digestion. The gas produced from mixed substrates became flammable with blue flame after 16 days of production, indicating that the ratio of methane gas generated with the three mixtures of fresh animal waste was higher than other gases produced.
Sustainable Agriculture Research, 2019
Agricultural mechanization and open livestock grazing contribute to soil compaction and consequen... more Agricultural mechanization and open livestock grazing contribute to soil compaction and consequently on crop productivity. This study used a greenhouse experiment to identify the effects of soil compaction on the growth, productivity and nutrient uptake of maize plant seedlings grown at three bulk density (1.17, 1.37, and 1.45 g cm-3) and three water contents (0.12, 0.18, and 0.30 g/g soil). Shoot elongation and leaf area decreased significantly by 27.1 and 67.8% respectively at high compaction (P<0.05). Fresh and dry root mass also decreased significantly at high compaction by 39.1 and 37.8% respectively. Increase in soil compaction also reduced the grain yield by 18.8%. The adverse soil conditions created by increasing soil compaction accounted for the reduction in nutrient uptake. Increase in penetration resistance of the soil reduced the plants ability to absorb nitrogen (13.5%), potassium (51.4%), magnesium (50.4%) and sodium (51.5%) whereas the concentration of calcium and ...
The environmental impact of locating two polluting sources of landfill (refuse dump) and petroche... more The environmental impact of locating two polluting sources of landfill (refuse dump) and petrochemicals on Alaba stream in Akure, Nigeria was assessed. This was due to the dependence of Alaba inhabitants and its environment on the stream for variety of uses. Twenty physio-chemical parameters were analyzed for wet and dry seasons respectively with three sampling points within 5m intervals from one another of the two polluting sources on the stream. The parameters included: colour, odour, taste, pH, temperature, turbidity, alkalinity, conductivity, dissolved oxygen (DO), biochemical oxygen demand (BOD 5 ) and total solids (TS). Others were chloride (CL - ), total dissolved solids (TDS), total suspended solids (TSS), lead (Pb), nitrate (NO 3 ), sulphate (SO 4 -2 ), oil and grease, E-coli and faecal coliform. Some of the parameters were determined in-situ while others were determined using APHA (2005) standard procedures and results obtained were subjected to statistical analysis. All t...
Conference Presentations by Obafemi Olubanjo
The Nigerian Institution of Agricultural Engineers South West Zone Held at The University of Ibadan,, Nigeria, between 30th -31st August, 2023, 2023
The rapid conversion of agricultural land to non-agricultural uses in industrialized countries an... more The rapid conversion of agricultural land to non-agricultural uses in industrialized countries and
escalating rates of land degradation in developing countries pose a significant threat to global
arable land. This study explores the feasibility and yield potential of hydroponic lettuce
production using a constructed non-circulating Kratky system as a response to this pressing
issue. Lettuce was cultivated in the Kratky system, with considerations for factors such as soil
pH, total dissolved solids (TDS), and electrical conductivity. The study aimed to determine the
appropriate nutrient solution for lettuce growth and assess water usage. Measurements were
taken for vegetative growth, yield, water and nutrient quantity, proximate and mineral
composition, as well as the physicochemical properties of the hydroponic nutrients. The results
revealed that lettuce cultivated in the Kratky system exhibited high mineral and proximate
composition. The pH of the nutrient solution gradually increased from 5.7 in the early stage to
6.2 in the vegetative stage and 6.4 in the maturity stage. TDS and electrical conductivity showed
an increasing trend throughout the growth stages. Essential plant nutrients such as nitrogen,
phosphorus, potassium, calcium, and magnesium were present in varying amounts at different
growth stages. Trace elements like iron, manganese, zinc, and copper were also present, although
in lower concentrations due to potential toxicity. Varying plant heights for lettuce were observed,
ranging from 1.17 mm to 1.97 mm. Water usage ranged from 3500 mm to 5300 mm, decreasing
as the weeks after planting increased while the water efficiency varies from 53.71 kg/m3
to 49.00
kg/m3
. Overall, the findings demonstrate the technical feasibility and potential of hydroponic
production of leafy vegetables, particularly lettuce, using a constructed non-circulating Kratky system. The study recommends the adoption of this sustainable method for leafy vegetable
production.
Keywords: Hydroponics, Lettuce, Kratky system, Fertigation
The Nigerian Institution of Agricultural Engineers South West Zone Held at The University of Ibadan,, Nigeria, between 30th -31st August, 2023., 2023
Many people lack the knowledge and selection of acceptable solid substrates for hydroponic jute m... more Many people lack the knowledge and selection of acceptable solid substrates for hydroponic jute mallow cultivation. As a result, this research comparatively assess the effect of organic solid substrates on the growth and yield of jute mallow (Corchorus olitorius L) under drip irrigation farming method. This research was carried out at the
2023 SEET CONFERENCE 041, 2023
This paper describes the use of weighing-type mini-lysimeters to measure the crop water demand of... more This paper describes the use of weighing-type mini-lysimeters to measure the crop water demand of rain-fed cucumber and okra. The mini-lysimeters were constructed from readily available materials like vehicle tubes filled with water and plastic tanks for the lysimeter tank, which were then connected to a weighing system using manometer glass tubes. The consumptive use of okra was between 2.97 mm/day to 26.79 mm/day with a seasonal average of 7.35 mm/day. The water uses of the cucumber crop also varied from 1.13 mm/day to 28.96 mm/day with a seasonal average of 5.79 mm/day. The okra and cucumber crops used 419.06 mm and 364.81 mm of water each season, representing 52.84% and 57.48% of the seasonal rainfall, respectively. Estimating crop water demand and other aspects of the soil water balance under rain-fed conditions is made easier by the use of a mini-lysimeter.
Keywords: Evapotranspiration; Rainfall; Drainage; Runoff depths; Lysimeters.
Uploads
Papers by Obafemi Olubanjo
This paper describes the use of weighing-type mini-lysimeters to measure the crop water demand of rain-fed cucumber and okra. The mini-lysimeters were constructed from readily available materials like vehicle tubes filled with water and plastic tanks for the lysimeter tank, which were then connected to a weighing system using manometer glass tubes. The consumptive use of okra was between 2.97 mm/day to 26.79 mm/day with a seasonal average of 7.35 mm/day. The water uses of the cucumber crop also varied from 1.13 mm/day to 28.96 mm/day with a seasonal average of 5.79 mm/day. The okra and cucumber crops used 419.06 mm and 364.81 mm of water each season, representing 52.84% and 57.48% of the seasonal rainfall, respectively. Estimating crop water demand and other aspects of the soil water balance under rain-fed conditions is made easier by the use of a mini-lysimeter.
Keywords: Evapotranspiration; Rainfall; Drainage; Runoff depths; Lysimeters.
Conference Presentations by Obafemi Olubanjo
escalating rates of land degradation in developing countries pose a significant threat to global
arable land. This study explores the feasibility and yield potential of hydroponic lettuce
production using a constructed non-circulating Kratky system as a response to this pressing
issue. Lettuce was cultivated in the Kratky system, with considerations for factors such as soil
pH, total dissolved solids (TDS), and electrical conductivity. The study aimed to determine the
appropriate nutrient solution for lettuce growth and assess water usage. Measurements were
taken for vegetative growth, yield, water and nutrient quantity, proximate and mineral
composition, as well as the physicochemical properties of the hydroponic nutrients. The results
revealed that lettuce cultivated in the Kratky system exhibited high mineral and proximate
composition. The pH of the nutrient solution gradually increased from 5.7 in the early stage to
6.2 in the vegetative stage and 6.4 in the maturity stage. TDS and electrical conductivity showed
an increasing trend throughout the growth stages. Essential plant nutrients such as nitrogen,
phosphorus, potassium, calcium, and magnesium were present in varying amounts at different
growth stages. Trace elements like iron, manganese, zinc, and copper were also present, although
in lower concentrations due to potential toxicity. Varying plant heights for lettuce were observed,
ranging from 1.17 mm to 1.97 mm. Water usage ranged from 3500 mm to 5300 mm, decreasing
as the weeks after planting increased while the water efficiency varies from 53.71 kg/m3
to 49.00
kg/m3
. Overall, the findings demonstrate the technical feasibility and potential of hydroponic
production of leafy vegetables, particularly lettuce, using a constructed non-circulating Kratky system. The study recommends the adoption of this sustainable method for leafy vegetable
production.
Keywords: Hydroponics, Lettuce, Kratky system, Fertigation
Keywords: Evapotranspiration; Rainfall; Drainage; Runoff depths; Lysimeters.