J. Omueti
University Of Ibadan,Ibadan Oyo State Nigeria, Agronomy, Faculty Member
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ABSTRACT While some composting had been practiced on a limited basis in Nigeria 50 years ago, the practice still is largely neglected. Farmers find it more convenient to use fertilizers because of the ease of carrying, storing and... more
ABSTRACT While some composting had been practiced on a limited basis in Nigeria 50 years ago, the practice still is largely neglected. Farmers find it more convenient to use fertilizers because of the ease of carrying, storing and applying. However, since 1986, there has been a major change in the composition of refuse in Nigeria. With greater numbers of people in the low socioeconomic groups scavenging on the refuse dumps collecting paper, metal, glass and plastics, the remaining refuse is mostly organic and ideal for making compost. Studies undertaken at the University of Ibadan reveal that once mobilized, communities can be effective in launching composting projects. Appropriate technology is favored in processing the wastes rather than extensive and, often unaffordable, mechanization.
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Research Interests: Biology and Soil Water
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160 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1976.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD
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An experiment was carried out to examine the effectiveness of four different composts formulated from poultry (PM) and cowdung (CD) manures as primary constituents and two bulking agents namely sawdust (SD) and sorted refuse (SR) on... more
An experiment was carried out to examine the effectiveness of four different composts formulated from poultry (PM) and cowdung (CD) manures as primary constituents and two bulking agents namely sawdust (SD) and sorted refuse (SR) on some yield components of maize for two cropping seasons. All compost mixtures were fortified with rock phosphate and urea. The compost treatments (PM/SD, PM/SR, CD/SD and CD/SR at ratio 3:1) were applied at 2.5 tonnes/ha, replicated three times with NPK (15:15:15) fertilizer applied at 300 kg/ha as reference treatment and a control (no compost, no fertilizer), all arranged in a randomized complete design. The results showed that the composts significantly increased (P<0.05) all the maize yield components measured for the two cropping seasons. The PM/SD and PM/SR produced a higher grain yield of 3326 and 3218 kg/ha, respectively, for the first cropping season and 1603 and 2423 kg/ha, respectively, for the second season compared to the co...
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A green house experiment was conducted to determine the magnesium releasing potential of soil of Edo State. Exhaustive cropping technique was used with maize as test crop. Twenty composite surface soil samples collected from... more
A green house experiment was conducted to determine the magnesium releasing potential of soil of Edo State. Exhaustive cropping technique was used with maize as test crop. Twenty composite surface soil samples collected from pre-classified sites were used for this study. From the study, exchangeable Mg decreased from an initial mean of 1.39 to a mean of 0.26cmol kg-1 soil after four successive croppings. Exchangeable Mg before cropping and the decrease in exchangeable Mg after four successive croppings were positively and significantly correlated with total update with “r” values of 0.937 *** and 0.992***, respectively. The only 4.30% of the total Mg that was taken up by maize plant during four successive croppings conceivably came from non-exchangeable sources. This was too small to meet its requirement. Incipient deficiency symptoms were associated with Mg content or concentration of less than 0.3% in plant; 0.28cmol kg-1 soil of IN NH4 OAc (PH7) extractable Mg or 5% Mg saturation...
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An experiment was carried out to examine the effectiveness of four different composts formulated from poultry (PM) and cowdung (CD) manures as primary constituents and two bulking agents namely sawdust (SD) and sorted refuse (SR) on some... more
An experiment was carried out to examine the effectiveness of four different composts formulated from poultry (PM) and cowdung (CD) manures as primary constituents and two bulking agents namely sawdust (SD) and sorted refuse (SR) on some yield components of maize for two cropping seasons. All compost mixtures were fortified with rock phosphate and urea. The compost treatments (PM/SD, PM/SR, CD/SD and CD/SR at ratio 3:1) were applied at 2.5 tonnes/ha, replicated three times with NPK (15:15:15) fertilizer applied at 300 kg/ha as reference treatment and a control (no compost, no fertilizer), all arranged in a randomized complete design. The results showed that the composts significantly increased (P<0.05) all the maize yield components measured for the two cropping seasons. The PM/SD and PM/SR produced a higher grain yield of 3326 and 3218 kg/ha, respectively, for the first cropping season and 1603 and 2423 kg/ha, respectively, for the second season compared to the cowdung-based com...
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Abstract In Nigeria and in some other tropical countries routine soil testing is at its infancy, therefore research into handling and processing techniques is very essential. For the investigation being reported, thirty surface (0–15cm)... more
Abstract In Nigeria and in some other tropical countries routine soil testing is at its infancy, therefore research into handling and processing techniques is very essential. For the investigation being reported, thirty surface (0–15cm) soils having different cropping histories and variable levels of P were collected from different ecological zones of South Western Nigeria and the following techniques using Bray's P1 and NH4F.HF solutions were investigated; shaking time, type of shaker, length of shaking, positioning of bottles in the shaker, lag period before filtering after shaking and time lag after colour development before P reading. The extractable P from all these techniques were correlated with P uptake in the greenhouse. The results indicated that 5 minutes shaking gave the best correlation with uptake (r= 0.91**) for Bray's P1 and 1 minute for NH4F.HF (r= 0.88**). Neither vertical nor horizontal placement affected the extractable P, but stirring gave a non‐significantly lower correlation. Lag pe...
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Abstract In order to set up a routine soil testing laboratory for advisory purpose, sample preparation and handling is very important. Potassium is one of the essential nutrients, whose handling’ has not been studied in Nigeria.... more
Abstract In order to set up a routine soil testing laboratory for advisory purpose, sample preparation and handling is very important. Potassium is one of the essential nutrients, whose handling’ has not been studied in Nigeria. Laboratory and greenhouse experiments were therefore set up to study the effect of sample preparation and handling on exchangeable K. The results have indicated that air drying at 72°F resulted in a significant increase in extractable K while even drying at 110°C for 24 hours resulted in similar values with those obtained for field moist samples. Correlation coefficients between K uptake by plants and exchangeable K determined from moist and oven dry samples were not significantly different from each other whereas there was significant correlation (r=0.904∗∗∗) between K uptake and exchangeable K determined from air‐dry samples. Under wetting‐ and drying, there was an increase in soil K. The mechanism for this is not understood. Furthermore no significant difference exists between ...
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Abstract The amounts of Mn, Pe and Al in H2O2 and NaOCl extracts during pretreatment of the soil for organic matter removal were determined. In addition acid ammonium oxalate extractable Mn, Fe and Al as well as amorphous aluminosilicates... more
Abstract The amounts of Mn, Pe and Al in H2O2 and NaOCl extracts during pretreatment of the soil for organic matter removal were determined. In addition acid ammonium oxalate extractable Mn, Fe and Al as well as amorphous aluminosilicates using boiling 0.5N NaOH procedure were determined on the residues. It was found that the oxides removed by NaOCl pretreatment were significantly lower than the amounts removed by H2O2 procedure. In the residue, Mn and Pe extractable by oxalate were less in the NaOcl treated soils than in those of H2O2. But in the case of amorphous aluminosilicates the result indicate that these soil constituents were more destroyed by NaOCl than H2O2‐ pretreatment. Therefore it was concluded that in specific mineralogical studies where the contents of amorphous aluminosilicates are desired the use of NaOCl for organic matter destruction should be avoided.
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... in the subhumid zone of Nigeria as a result of poor nutrition arising from the poor fertility status of the soils (Wild, 1971; Mohamed-Saleem et al. 1986; Adeoye and Mohamed-Saleem, 1990; Tarawali, 1991). The soils are... more
... in the subhumid zone of Nigeria as a result of poor nutrition arising from the poor fertility status of the soils (Wild, 1971; Mohamed-Saleem et al. 1986; Adeoye and Mohamed-Saleem, 1990; Tarawali, 1991). The soils are characteristically low in cation exchange capacity (CEC), ...
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... They were then covered with clean polytethylene sheets. Following studies by Okeya (1979),Ayodele (1980), and Adeoye (1986), the following days of incubation were used: 1, 7, and 42 days. Page 4. ... K Incub. Added Tim» cmol/kg days... more
... They were then covered with clean polytethylene sheets. Following studies by Okeya (1979),Ayodele (1980), and Adeoye (1986), the following days of incubation were used: 1, 7, and 42 days. Page 4. ... K Incub. Added Tim» cmol/kg days 0.00 0.11 0.22 0.45 0.90 1.80 ...
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Composting of animal manure had been considered a sustainable alternative method for recycling organic waste. However the process involved had been associated with greenhouse gas emission (CO2, N2O and CH4) which play an active role in... more
Composting of animal manure had been considered a sustainable alternative method for recycling organic waste. However the process involved had been associated with greenhouse gas emission (CO2, N2O and CH4) which play an active role in global warming. This study evaluated CO2 emissions from biochar-manure co-compost production. Biochar (from rice husk) and manure were mixed in a ratio of 3:1 v/v to achieve a range of different co-compost mixtures. The treatments and controls in triplicates of 18 units were arranged in a complete randomize design. All treatments were incubated at around 28 oC and turned every two days for 2 weeks, and later five days for 39 days. CO2 production in the compost bins was measured by trapping the evolved gas in 5M NaOH. Total CO2 emissions varied over time with higher rates at the beginning of the composting process. Within the first 7 days, total CO2 emissions (587 mg/m2) from cow dung alone was not significantly different from cow dung plus biochar (50...
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Asbestos-rich serpentinitic sediments weather rapidly in acid environments and in the process trace metals are released and smectite clays are formed in the soils. A study was carried out in the Sumas River Basin in northwestern... more
Asbestos-rich serpentinitic sediments weather rapidly in acid environments and in the process trace metals are released and smectite clays are formed in the soils. A study was carried out in the Sumas River Basin in northwestern Washington State, where a landslide has exposed asbestos-rich serpentinitic rocks. Between 1975 and 1985 the river draining the landslide has flooded several agricultural fields
Research Interests: Environmental Science, Trace Metals, Biological Sciences, Environmental Sciences, Magnesium, and 12 moreChromium, Nickel, Energy Dispersive X-Ray Analysis, River Basin, Acid Soil, Room Temperature, Washington State, Citric Acid, Acid Neutralizing Capacity, X Ray Spectroscopy, Oxalic acid, and Organic Acid
Composting of animal manure had been considered a sustainable alternative method for recycling organic waste. However the process involved had been associated with greenhouse gas emission (CO2, N2O and CH4) which play an active role in... more
Composting of animal manure had been considered a sustainable alternative method for recycling organic waste. However the process involved had been associated with greenhouse gas emission (CO2, N2O and CH4) which play an active role in global warming. This study evaluated CO2 emissions from biochar-manure co-compost production. Biochar (from rice husk) and manure were mixed in a ratio of 3:1 v/v to achieve a range of different co-compost mixtures. The treatments and controls in triplicates of 18 units were arranged in a complete randomize design. All treatments were incubated at around 28 oC and turned every two days for 2 weeks, and later five days for 39 days. CO2 production in the compost bins was measured by trapping the evolved gas in 5M NaOH. Total CO2 emissions varied over time with higher rates at the beginning of the composting process. Within the first 7 days, total CO2 emissions (587 mg/m2) from cow dung alone was not significantly different from cow dung plus biochar (50...
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... JOY Ipava Cisne Muscatine Elliott Herrick Sable Alford (acid) Alford (limed) Fayette Seaton Blount Hosmer Tamalco A 365 B,, 285 B,, 188 A 444 B, 469 B,, 316 A 493 B,, 508 B,, 408 A 358 A 625 A 173 A 36 1 A 132 A 100 A 192 A 149 A 267... more
... JOY Ipava Cisne Muscatine Elliott Herrick Sable Alford (acid) Alford (limed) Fayette Seaton Blount Hosmer Tamalco A 365 B,, 285 B,, 188 A 444 B, 469 B,, 316 A 493 B,, 508 B,, 408 A 358 A 625 A 173 A 36 1 A 132 A 100 A 192 A 149 A 267 A 200 A 521 ...
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ABSTRACT The mineralogy of the clay fraction (&lt;2 μm) of nine soil samples representing three physiographic positions of a toposequence in Ochon, south-eastern Nigeria, was determined by transmission electron microscopy and X-ray... more
ABSTRACT The mineralogy of the clay fraction (&lt;2 μm) of nine soil samples representing three physiographic positions of a toposequence in Ochon, south-eastern Nigeria, was determined by transmission electron microscopy and X-ray diffraction.Soils in the crest and middle slopes (pedons TE1 and TE2, respectively) of the toposequence, formed over fine-grained sandstone, were coarse-textured, well-drained and acidic and had low effective cation exchange capacity and percentage base saturation. Kaolinite, mica, quartz, goethite and gibbsite were the principal minerals identified in the clay fraction of these soils. Soils in the valley bottom (pedon TE3) formed over arenaceous shale were, on the other hand, fine-textured, poorly drained and weakly acidic with higher cation exchange capacity and percentage base saturation. Their clay fraction mineralogy was similar to that of the well-drained upland soils but additionally included feldspar and smectite/vermiculite mixed layer minerals.Mixed cropping of yam, cassava, maize and other annuals under traditional methods was carried out on the drier, well-drained crest and upper slopes while sole cropping of lowland rice occurred in the poorly drained, more fertile valley-bottom site. The valley-bottom soils show greater potential for improvement in agricultural productivity under good management than the upland soils.
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The effect of calcium (Ca)/magnesium (Mg) ratio in the soil on Mg availability, yield, and yield components of maize (Zea mays L.) was investigated both in the greenhouse and the field at eight different Ca/Mg ratios ranging from 1∶1 and... more
The effect of calcium (Ca)/magnesium (Mg) ratio in the soil on Mg availability, yield, and yield components of maize (Zea mays L.) was investigated both in the greenhouse and the field at eight different Ca/Mg ratios ranging from 1∶1 and 8∶1. In the greenhouse, exchangeable Ca/Mg ratios of 2∶1 to 3∶1 gave optimum yield of maize without Mg‐deficiency symptoms. The
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ABSTRACT A greenhouse experiment was conducted to determine the critical deficiency levels of potassium (K) in the subhumid zone soils for predicting response of a mixture of Andropogon gayanus and Stylosanthes hamata cv. Verano to K... more
ABSTRACT A greenhouse experiment was conducted to determine the critical deficiency levels of potassium (K) in the subhumid zone soils for predicting response of a mixture of Andropogon gayanus and Stylosanthes hamata cv. Verano to K application. Twenty coarse textured soils, having loamy sand to sandy loam textures and with exchangeable K contents ranging from 0.08 to 0.97 cmol/kg, were used. Two rates of K applied were 0 and 80 mg K/kg. Application of K on soils testing less than 0.18 cmol/kg significantly increased the dry matter yields of both Andropogon and stylo tops. Soil K was significantly related to relative yields of Sole Andropogon (r = 0.60**), sole stylo (r = 0.78***), and Andropogon/stylo mixture (r = 0.77***). There was a high correlation between the K concentration in plant tissue and the relative yields of sole Andropogon (r = 0.68**), sole stylo (r = 0.67**), Andropogon in mixture (r = 0.65**), and stylo in mixture (r = 0.64**). The graphical model of Gate and Nelson indicated the critical levels of the available form of K in soil to be 0.18, 0.20, and 0.21 cmol/kg for sole Andropogon, sole stylo and Andropogon/stylo mixture, respectively. The critical levels for K in plant tissues were also determined to be 1.30, 2.03, 1.38 and 1.86% for sole Andropogon, sole stylo Andropogon in mixture, and stylo in mixture, respectively.
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ABSTRACT Twenty surface soils (0 to 15 cm), selected to represent a wide range of available potassium (K) status and three different land‐use systems (fodder bank, continuously fertilized cropped land and fallow land) across the subhumid... more
ABSTRACT Twenty surface soils (0 to 15 cm), selected to represent a wide range of available potassium (K) status and three different land‐use systems (fodder bank, continuously fertilized cropped land and fallow land) across the subhumid zone of Nigeria, were used for the investigation. Laboratory and greenhouse studies were carried out to assess their K status. Available, non‐exchangeable, and total K were determined. The supplying power of the soils was assessed by exhaustive cropping in the greenhouse using Stylosanthes hamata cv. Verano as the indicator plant. While 75% of fodder banks sampled had available K less than 0.20 cmol/kg, only 50% and 13% of continuously fertilized cropped and fallow lands, respectively, had available K less than 0.20 cmol/kg. Potassium weathering coefficient was highest at the lowest exchangeable K and highest [calcium (Ca) + magnesium (Mg)]/K ratio. Total K ranged from 2.30 to 47.06 cmol/kg, with available K forming 1.47% of the total K. The amount of non‐exchangeable K released and taken up by stylo plant accounted for 23.3 to 83.6% of the total K uptake.