The ability of cyanobacteria to fix N 2 and produce exopolysacharides varies widely among differe... more The ability of cyanobacteria to fix N 2 and produce exopolysacharides varies widely among different strains. The objective of this study was to identify and isolate cyanobacteria strains with ability to fix N 2 and produce exopolysaccharides with a view to evaluate them for their biofertilization and conditioning potential of degraded soils in arid and semi arid areas of the Eastern Cape Province, South Africa. Cyanobacteria were isolated from four sites by culture and plating techniques using growth media BG11 for all strains and BG110 for atmospheric N2=fixing strains. The number s of strains isolated were 2, 28, 35, and 32 for Guquka, Hertzog, Fort Cox College, and Qunu soils, respectively. Only three of the 97 strains had bioconditioning and biofertilization potential emphasizing the importance of screening in order to identify cyanobacteria strains suitable for improving the physical and chemical fertility of soils. Other isolated cyanobacteria strains produced no exopolysaccha...
Innovations as Key to the Green Revolution in …, 2011
The introduction of urine diversion toilets in South Africa has created opportunities for the rec... more The introduction of urine diversion toilets in South Africa has created opportunities for the recycling of human urine in agriculture. One of such possibilities is the use of human urine as a source of nitrogen during the composting of organic wastes. This study evaluated the ...
Earthworms play a pivotal role in the regulation of soil health. Studies that explore the effects... more Earthworms play a pivotal role in the regulation of soil health. Studies that explore the effects of conservation agriculture (CA) principles on earthworms under the semi-arid climate of the central Eastern Cape (EC) of South Africa (SA) are limited. Therefore, this study investigated the effects of tillage, crop rotations, and residue management on earthworms’ abundance and species richness. The study design followed a split-split plot with three replicates. The main plot was allocated to tillage treatment, which had conventional tillage (CT) and no-tillage (no-till) as factors. Crop rotation treatment was allocated to a subplot, and had maize (Zea mays)–fallow–maize (MFM), maize–fallow–soybean (Glycine max) (MFS), maize–wheat (Triticum aestivum)–maize (MWM), and maize–wheat–soybean (MWS). Residue management was in the sub-subplot with residue retention and residue removal. The study was carried out over four cropping seasons: summer 2015–2016, winter 2016, spring 2016, and summer ...
Vermicomposting using Eisenia fetida has been shown to improve phosphorus mineralization from roc... more Vermicomposting using Eisenia fetida has been shown to improve phosphorus mineralization from rock phosphate (RP). There is, however, a lack of information on the potential of integrating microbial inoculants like phosphate-solubilizing bacteria (PSB) during vermicomposting as a way of improving vermidegradation, and the release of nutrients from igneous RP-amended composts. This study evaluated the potential of using Eisenia fetida and Pseudomonas fluorescence in enhancing the vermidegradation, and nutrient release in igneous RP- amended cow and pig manure-based vermicomposts at a C/N ratio of 30. Compost maturity, nutrient and phytotoxicity parameters were measured to determine vermicompost quality. Final vermicompost results showed that the pig manure treatments achieved greater maturity as indicated by lower C/N of 10.3, high humification index (HI) of 7.6%, and humification ratio (HR) of 12.89% in the treatment with E. fetida and P. fluorescence. The inclusion of E. fetida alon...
In organic soil fertility management, rock phosphate (RP) is gaining momentum as an acceptable ph... more In organic soil fertility management, rock phosphate (RP) is gaining momentum as an acceptable phosphorus source, though much of this P is not bioavailable for plant uptake, particularly in igneous RP. This study evaluated the nutrient solubilization, biodegradation and heavy metal concentration when cow dung - waste paper mixture amended with increasing rates of igneous RP was vermicomposted with . The cow dung was optimized to a C/N ratio of 30 using waste paper and amended with RP to provide 0%; 2%; 4% and 8% of elemental phosphorus on a dry w/w basis. Incorporation of RP at 2% and 8% P enhanced compost biodegradation resulting in a 12% and 22% significantly ( < 0.001) lower final C/N ratio, respectively, compared to the control; together with higher humification parameters. Amending the cow dung - waste paper mixture with 2%, 4% and 8% P as rock phosphate, resulted in a 39%; 50% and 65% more resin extractable P, respectively, relative to the control. Similarly, the bicarbonat...
Due to rapid expansion in the poultry industry, production of poultry manure has also consequentl... more Due to rapid expansion in the poultry industry, production of poultry manure has also consequently increased, resulting in unplanned disposal of this manure to the soil in some cases, with possible negative environmental consequences. In this study, 10 separate poultry manure samples were collected from different sites located in the central Eastern Cape, South Africa and characterized for chemical and phytotoxic properties. The poultry manures had an average neutral pH (range 6.94 - 7.97) whilst the electrical conductivity was highly variable from 2.45 dS/m to 12.3 dS/m between the 10 sites. The high conductivity values recorded in some of the manures indicate that caution may need to be practiced when directly applying these manure to the soil, to avoid buildup of soluble salts. All samples showed a very high concentration of total P (1963.1 mg/kg - 2644.1 mg/kg) with the plant available fraction ranging from 21.3% - 37.7% of the total P. All the heavy metals measured (Cr, Cu, Ni,...
Environmental science and pollution research international, 2018
Vermicomposting is a bio-oxidative process that involves the action of mainly epigeic earthworm s... more Vermicomposting is a bio-oxidative process that involves the action of mainly epigeic earthworm species and different micro-organisms to accelerate the biodegradation and stabilization of organic materials. There has been a growing realization that the process of vermicomposting can be used to greatly improve the fertilizer value of different organic materials, thus, creating an opportunity for their enhanced use as organic fertilizers in agriculture. The link between earthworms and micro-organisms creates a window of opportunity to optimize the vermi-degradation process for effective waste biodegradation, stabilization, and nutrient mineralization. In this review, we look at up-to-date research work that has been done on vermicomposting with the intention of highlighting research gaps on how further research can optimize vermi-degradation. Though several researchers have studied the vermicomposting process, critical parameters that drive this earthworm-microbe-driven process which ...
ABSTRACT INTRODUCTION During coal combustion at electricity power stations, 70% of the solid resi... more ABSTRACT INTRODUCTION During coal combustion at electricity power stations, 70% of the solid residue is fly ash with South Africa generating more than 26 million tons of fly ash annually, posing serious disposal challenges, as only 5% is utilized in the construction industry. However, limited research is available on potential effects and uses of South African fly ashes in agriculture and land reclamation. MATERIALS AND METHODS Total elemental concentration was determined using ICP-OES and Skalar CFA following microwave digestion. Plant available elements were extracted using DTPA-TEA and Ammonium nitrate, whilst plant available P was extracted using Olsen method. Elemental release was estimated using an incubation experiment at 0%, 5%, 10% and 20% fly ash incorporation rate to soil. RESULTS AND DISCUSSION For all fly ash samples, total P content ranged from 553.3 to 1514 mg P/kg and Olsen extractable P from 130 to 345.5 mg P kg-1. Matla fly ash had a higher total and extractable P of 1028 mg kg-1 and 256.15 mg kg-1 with the available P being 24.9% of total P. Application of fly ash at 10% incorporation rate raised extractable P content of the soil from a P deficient level to levels above the more than 25 mg kg -1 critical for most crops (Johnson et al. 2013). With a few exceptions, the heavy metal content of the fly ash samples followed the order Fe&gt; Cr&gt;Pb&gt; Ni&gt; Cu&gt; Zn. The DPTA extractable levels for the elements were low and less than 2mg kg-1 except for Fe which had levels ranging from 4.8 to 136 mg Fe kg-1. Except for Cr, all heavy metals (Cu, Pb, Fe, Ni) showed significantly (P = 0.05) low extractability at all fly ash incorporation rates compared to the soil alone control, suggesting possible precipitation of the elements.The results obtained showed that, excluding Pb, all fly ash samples studied, when incorporated into soil at 10% or less, the heavy metal load was below the maximum permissible levels recommended in South Africa. CONCLUSION These results suggest that the South African fly ashes studied can be an important source of essential elements like P with minimum risk to soil contamination from heavy metal release.
Communications in Soil Science and Plant Analysis, 2000
Greenhouse experiments were conducted to evaluate the agronomic effectiveness of Panda Hills phos... more Greenhouse experiments were conducted to evaluate the agronomic effectiveness of Panda Hills phosphate rock (PPR) from southwest Tanzania, its mixture with triple superphosphate (TSP), and a compacted mixture of Panda PR and TSP (PPR+TSP) for wheat, rape, maize, and soybean on two United States soils (Hiwassee and Windthorst). The mixture of Panda PR and TSP was prepared by mixing ground
The ability of cyanobacteria to fix N 2 and produce exopolysacharides varies widely among differe... more The ability of cyanobacteria to fix N 2 and produce exopolysacharides varies widely among different strains. The objective of this study was to identify and isolate cyanobacteria strains with ability to fix N 2 and produce exopolysaccharides with a view to evaluate them for their biofertilization and conditioning potential of degraded soils in arid and semi arid areas of the Eastern Cape Province, South Africa. Cyanobacteria were isolated from four sites by culture and plating techniques using growth media BG11 for all strains and BG110 for atmospheric N2=fixing strains. The number s of strains isolated were 2, 28, 35, and 32 for Guquka, Hertzog, Fort Cox College, and Qunu soils, respectively. Only three of the 97 strains had bioconditioning and biofertilization potential emphasizing the importance of screening in order to identify cyanobacteria strains suitable for improving the physical and chemical fertility of soils. Other isolated cyanobacteria strains produced no exopolysaccha...
Innovations as Key to the Green Revolution in …, 2011
The introduction of urine diversion toilets in South Africa has created opportunities for the rec... more The introduction of urine diversion toilets in South Africa has created opportunities for the recycling of human urine in agriculture. One of such possibilities is the use of human urine as a source of nitrogen during the composting of organic wastes. This study evaluated the ...
Earthworms play a pivotal role in the regulation of soil health. Studies that explore the effects... more Earthworms play a pivotal role in the regulation of soil health. Studies that explore the effects of conservation agriculture (CA) principles on earthworms under the semi-arid climate of the central Eastern Cape (EC) of South Africa (SA) are limited. Therefore, this study investigated the effects of tillage, crop rotations, and residue management on earthworms’ abundance and species richness. The study design followed a split-split plot with three replicates. The main plot was allocated to tillage treatment, which had conventional tillage (CT) and no-tillage (no-till) as factors. Crop rotation treatment was allocated to a subplot, and had maize (Zea mays)–fallow–maize (MFM), maize–fallow–soybean (Glycine max) (MFS), maize–wheat (Triticum aestivum)–maize (MWM), and maize–wheat–soybean (MWS). Residue management was in the sub-subplot with residue retention and residue removal. The study was carried out over four cropping seasons: summer 2015–2016, winter 2016, spring 2016, and summer ...
Vermicomposting using Eisenia fetida has been shown to improve phosphorus mineralization from roc... more Vermicomposting using Eisenia fetida has been shown to improve phosphorus mineralization from rock phosphate (RP). There is, however, a lack of information on the potential of integrating microbial inoculants like phosphate-solubilizing bacteria (PSB) during vermicomposting as a way of improving vermidegradation, and the release of nutrients from igneous RP-amended composts. This study evaluated the potential of using Eisenia fetida and Pseudomonas fluorescence in enhancing the vermidegradation, and nutrient release in igneous RP- amended cow and pig manure-based vermicomposts at a C/N ratio of 30. Compost maturity, nutrient and phytotoxicity parameters were measured to determine vermicompost quality. Final vermicompost results showed that the pig manure treatments achieved greater maturity as indicated by lower C/N of 10.3, high humification index (HI) of 7.6%, and humification ratio (HR) of 12.89% in the treatment with E. fetida and P. fluorescence. The inclusion of E. fetida alon...
In organic soil fertility management, rock phosphate (RP) is gaining momentum as an acceptable ph... more In organic soil fertility management, rock phosphate (RP) is gaining momentum as an acceptable phosphorus source, though much of this P is not bioavailable for plant uptake, particularly in igneous RP. This study evaluated the nutrient solubilization, biodegradation and heavy metal concentration when cow dung - waste paper mixture amended with increasing rates of igneous RP was vermicomposted with . The cow dung was optimized to a C/N ratio of 30 using waste paper and amended with RP to provide 0%; 2%; 4% and 8% of elemental phosphorus on a dry w/w basis. Incorporation of RP at 2% and 8% P enhanced compost biodegradation resulting in a 12% and 22% significantly ( < 0.001) lower final C/N ratio, respectively, compared to the control; together with higher humification parameters. Amending the cow dung - waste paper mixture with 2%, 4% and 8% P as rock phosphate, resulted in a 39%; 50% and 65% more resin extractable P, respectively, relative to the control. Similarly, the bicarbonat...
Due to rapid expansion in the poultry industry, production of poultry manure has also consequentl... more Due to rapid expansion in the poultry industry, production of poultry manure has also consequently increased, resulting in unplanned disposal of this manure to the soil in some cases, with possible negative environmental consequences. In this study, 10 separate poultry manure samples were collected from different sites located in the central Eastern Cape, South Africa and characterized for chemical and phytotoxic properties. The poultry manures had an average neutral pH (range 6.94 - 7.97) whilst the electrical conductivity was highly variable from 2.45 dS/m to 12.3 dS/m between the 10 sites. The high conductivity values recorded in some of the manures indicate that caution may need to be practiced when directly applying these manure to the soil, to avoid buildup of soluble salts. All samples showed a very high concentration of total P (1963.1 mg/kg - 2644.1 mg/kg) with the plant available fraction ranging from 21.3% - 37.7% of the total P. All the heavy metals measured (Cr, Cu, Ni,...
Environmental science and pollution research international, 2018
Vermicomposting is a bio-oxidative process that involves the action of mainly epigeic earthworm s... more Vermicomposting is a bio-oxidative process that involves the action of mainly epigeic earthworm species and different micro-organisms to accelerate the biodegradation and stabilization of organic materials. There has been a growing realization that the process of vermicomposting can be used to greatly improve the fertilizer value of different organic materials, thus, creating an opportunity for their enhanced use as organic fertilizers in agriculture. The link between earthworms and micro-organisms creates a window of opportunity to optimize the vermi-degradation process for effective waste biodegradation, stabilization, and nutrient mineralization. In this review, we look at up-to-date research work that has been done on vermicomposting with the intention of highlighting research gaps on how further research can optimize vermi-degradation. Though several researchers have studied the vermicomposting process, critical parameters that drive this earthworm-microbe-driven process which ...
ABSTRACT INTRODUCTION During coal combustion at electricity power stations, 70% of the solid resi... more ABSTRACT INTRODUCTION During coal combustion at electricity power stations, 70% of the solid residue is fly ash with South Africa generating more than 26 million tons of fly ash annually, posing serious disposal challenges, as only 5% is utilized in the construction industry. However, limited research is available on potential effects and uses of South African fly ashes in agriculture and land reclamation. MATERIALS AND METHODS Total elemental concentration was determined using ICP-OES and Skalar CFA following microwave digestion. Plant available elements were extracted using DTPA-TEA and Ammonium nitrate, whilst plant available P was extracted using Olsen method. Elemental release was estimated using an incubation experiment at 0%, 5%, 10% and 20% fly ash incorporation rate to soil. RESULTS AND DISCUSSION For all fly ash samples, total P content ranged from 553.3 to 1514 mg P/kg and Olsen extractable P from 130 to 345.5 mg P kg-1. Matla fly ash had a higher total and extractable P of 1028 mg kg-1 and 256.15 mg kg-1 with the available P being 24.9% of total P. Application of fly ash at 10% incorporation rate raised extractable P content of the soil from a P deficient level to levels above the more than 25 mg kg -1 critical for most crops (Johnson et al. 2013). With a few exceptions, the heavy metal content of the fly ash samples followed the order Fe&gt; Cr&gt;Pb&gt; Ni&gt; Cu&gt; Zn. The DPTA extractable levels for the elements were low and less than 2mg kg-1 except for Fe which had levels ranging from 4.8 to 136 mg Fe kg-1. Except for Cr, all heavy metals (Cu, Pb, Fe, Ni) showed significantly (P = 0.05) low extractability at all fly ash incorporation rates compared to the soil alone control, suggesting possible precipitation of the elements.The results obtained showed that, excluding Pb, all fly ash samples studied, when incorporated into soil at 10% or less, the heavy metal load was below the maximum permissible levels recommended in South Africa. CONCLUSION These results suggest that the South African fly ashes studied can be an important source of essential elements like P with minimum risk to soil contamination from heavy metal release.
Communications in Soil Science and Plant Analysis, 2000
Greenhouse experiments were conducted to evaluate the agronomic effectiveness of Panda Hills phos... more Greenhouse experiments were conducted to evaluate the agronomic effectiveness of Panda Hills phosphate rock (PPR) from southwest Tanzania, its mixture with triple superphosphate (TSP), and a compacted mixture of Panda PR and TSP (PPR+TSP) for wheat, rape, maize, and soybean on two United States soils (Hiwassee and Windthorst). The mixture of Panda PR and TSP was prepared by mixing ground
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