The study was prompted by concerns that soil compaction in horticultural fields at the University... more The study was prompted by concerns that soil compaction in horticultural fields at the University research farm was limiting the performance of fruit trees and vegetable crops after fifteen years of conventional tillage with tractors. Soil penetrometer resistance and bulk density were measured in the profiles of three adjacent fields (vegetable, orchard & vineyard). Over the years, tractor traffic was used in the vegetable field and orchard for seedbed preparation and weeding respectively, while the vineyard was not trafficked. Higher soil compaction was evident in the orchard and vegetable fields compared to vineyard. The location of compacted layers within the profiles was related to the nature of tractor traffic. There was subsoil compaction in the orchard and vegetable fields while shallow compaction was observed in the vineyard. Apart from tractor traffic, low organic matter content and the hardsetting behavior of the soil could have exacerbated the compaction. It was recommended that controlled traffic and deep ripping should be adopted, to not only ameliorate the existing compaction, but also sustain the productivity of the soils.
The use of medicinal plants for contraception remains a common practice among South African ethni... more The use of medicinal plants for contraception remains a common practice among South African ethnic groups. The present study assessed the phytochemical profile, cytotoxicity, acute oral toxicity and efficacy of a herbal mixture used for contraception by the Batswana of South Africa. An aqueous extract was prepared from equal quantities (in terms of weight) of Bulbine frutescens (roots), Helichrysum caespititium (leaves) and Teucrium trifidum (leaves) based on a recipe used by traditional health practitioners. The phytochemical profiles of the freeze-dried herbal mixture were analyzed using gas chromatography–mass spectrometry (GC-MS). In addition, cytotoxicity was determined using an MTT assay on Vero cells and in vivo contraceptive efficacy was evaluated using seven Sprague Dawley rats per control and treatment groups. The control group received distilled water while test groups received 5, 50 and 300 mg/kg of the herbal mixture, which was administered orally once a day for three c...
Animal manure is a key input for soil fertility management among small-scale crop farmers in Sout... more Animal manure is a key input for soil fertility management among small-scale crop farmers in South Africa. However, one of the misgivings that farmers have about the use of fresh animal manure in crop fields is that it encourages growth and proliferation of diverse weed species. Cattle, goat and sheep manure was aerobically composted in windrows over a 10-week period and the emergence and species diversity of weeds were compared with that of un-composted manure. Composting reduced the total number of weeds by an average of 66.3%, 85.1% and 84.2% in cattle, goat and sheep manure, respectively. There were on average six broadleaved weeds to one grass weed emerging in the composted manure. Composting reduced the diversity of weed species by 62% across the three manure types. The highest reduction in species composition was observed in sheep (75%) and goat (67%) manures compared to cattle (40%) manure. There were no grass weed species in the composted goat and sheep manures. The study c...
Cleome gynandra is an African indigenous leafy vegetable that is widely consumed by rural househo... more Cleome gynandra is an African indigenous leafy vegetable that is widely consumed by rural households in South Africa but there is a dearth of information on its cultivation and management. This study was aimed at determining the effects of applying ruminant kraal manure (cattle, goat and control) in combination with harvesting techniques (cutting edible tender tips only, cutting all leaves and cutting all the leaves but once at the end of the growing period) on biomass yield of leaves. Plants were grown in large PVC pots and leaves were cut five times before the final harvest. Application of both cattle and goat manure (50:50 by volume, soil: manure) significantly increased leaf biomass yields compared with the control. Plants that were grown in soil amended with goat manure produced significantly higher total fresh leaf yield (470.86 g pot -1 ) than those under cattle manure (328.42 g pot -1 ). The yields in the treatments with manure increased progressively with each harvesting wh...
African indigenous leafy vegetables have the important role of providing essential minerals, vita... more African indigenous leafy vegetables have the important role of providing essential minerals, vitamins and amino acids in diets of poor smallholder farmer households in sub-Saharan Africa. A study was conducted to quantify the influence of applying cattle and goat manure on the biomass yields and crude protein content of two commonly used African leafy vegetables (Cleome gynandra and Amaranthus hybridus) when subjected to varying leaf cutting management. Treatments for each vegetable consisted of a combination of three manures (control, cattle and goat) and three cutting regimes (cutting edible leaves, all harvestable leaves and cut only at the end) utilised in randomised block design. The results showed significant increase in leaf biomass yields and crude protein content of both vegetables due to manure application. Goat manure was superior to cattle manure due to its higher quality in terms of nutrient content and lower C:N ratio. Cutting the edible leaves more frequently, every f...
In Africa, indigenous methods of contraception continue to play a significant role in preventing ... more In Africa, indigenous methods of contraception continue to play a significant role in preventing unwanted pregnancies despite the introduction and popularity of modern contraceptives. The current review identified the common techniques and practices of African indigenous contraception, and examined their mechanisms and reasons for use. We searched data bases such as Google Scholar, Scopus, Web of Science, EBSCohost, African Journals, Science Direct, textbooks, thesis and dissertations for research articles on African indigenous contraception. The six common techniques of African indigenous contraception included periodic abstinence, withdrawal, breastfeeding, use of herbs, postpartum abstinence and waist bands, whilst practices relate to child (birth) spacing, postponement of first birth (virginity), stopping of reproduction and indigenous emergency contraception. Mother and infant health was stated as one of the reasons for using African indigenous contraception. African indigenous...
The influence of root growth and water regime on the formation of aggregates was studied in modif... more The influence of root growth and water regime on the formation of aggregates was studied in modified minirhizotrons under controlled conditions. Two soils, a black earth (67% clay) and a red-brown earth (19% clay) were ground and forced through a 0.5 mm sieve. Ryegrass, pea and wheat were grown for fifteen wetting and drying (wd) cycles for 5 months. Another set of minirhizotrons was not planted and served as a control. Measurements of aggregate size distribution (ASD), aggregate tensile strength (ATS), aggregate stability (AS), aggregate bulk density (ABD) and organic carbon (OC) were made on single aggregates of the 2–4 mm fraction. The results showed that aggregates of the black earth which has a high clay content and shrink/swell properties had more smaller aggregates with higher ATS, AS and ABD than those from the red-brown earth. It was also found that for both soils: (1) w/d cycles and higher root length density (RLD) increased the proportions of smaller aggregates and aggregate strength; (2) differences in the ability of the plant species to influence aggregation was evident and seemed to be related to the RLD. The RLD was in the order ryegrass > wheat > pea. Mechanisms likely to be involved in processes of aggregate formation and stabilization are discussed. They include cracking of soil due to tensile stresses generated during drying of a shrinking soil; changes in pore water pressure within the soil mass caused by water uptake by plant roots generating effective stresses; and biological processes associated with plant roots and root exudates.
The effects of Aloe ferox, Agave sisalana and Gunnera perpensa on haematological and biochemical ... more The effects of Aloe ferox, Agave sisalana and Gunnera perpensa on haematological and biochemical parameters of village chickens naturally infected with Heterakis gallinarum were evaluated. One hundred and twelve mature village chickens were randomly allotted into 14 groups of 8 chickens. Group 1 and 2 were orally administered 1 mL distilled water for 4 consecutive days and 1 mL mebendazole (once), respectively. Groups 3-6 received 1 mL orally of aqueous leaf extract of A. ferox for 4 consecutive days, groups 7-10 A. sisalana and 11-14 G. perpensa in graded doses of 50, 100, 200 and 400 mg/kg, respectively. Blood was collected into vacutainers in triplicate, from the wing veins on day 0, 7 and 14. Data was analysed using general linear model of statistical analyses system. Chickens offered A. sisalana (200 mg/kg) had highest alanine transaminase (ALT) value (P < 0.05; 7.50 ± 0.406 U/l) on day 0. On day 7 and 14, there was no difference in ALT values (P >0.05). Significant diffe...
A field experiment was conducted to evaluate the influence of root diameter on the ability of roo... more A field experiment was conducted to evaluate the influence of root diameter on the ability of roots of eight plant species to penetrate a compacted subsoil below a tilled layer. The soil was a fine sandy loam red-brown earth with a soil strength of about 3.0 MPa (at water content of 0.13 kg kg-1, corresponding to 0.81 plastic limit) at
Simeon Albert Materechera Crop Science Department, Faculty of Agriculture, Science & Technology, ... more Simeon Albert Materechera Crop Science Department, Faculty of Agriculture, Science & Technology, North-West University (Mafikeng Campus), P/B X2046, Mmabatho, 2735, Republic of South Africa Tel/fax: +27183843806; E-mail: Albert.Materechera@nwu.ac.za ABSTRACT As is the case with many other countries in sub-Saharan Africa, crop production among small scale farmers, especially those in semi-arid regions of South Africa, is hampered by predominance of extreme climate (low, irregular & erratic rainfall), low inherent soil fertility and low use of mineral fertilizers. However, the small scale farmers have developed a range of indigenous knowledge and practices which have played a pivotal role in the management of soil fertility for sustaining crop productivity. This study sought to establish and document these strategies in four farming districts located in semi-arid areas of the country. It was found that farmers use locally adaptable and cost effective strategies including animal manure...
Current Opinion in Environmental Sustainability, 2012
ABSTRACT Continuing soil degradation remains a serious threat to future food security. Yet, globa... more ABSTRACT Continuing soil degradation remains a serious threat to future food security. Yet, global soil degradation assessments are based on qualitative expert judgments or remotely sensed quantitative proxy values that suffice to raise awareness but are too coarse to identify appropriate sustainable land management interventions. Studies in China and Sub Saharan Africa illustrate the considerable impact of degradation on crop production but also point to the need for solutions dependent on location specific agro-ecological conditions and farming systems.The development of a comprehensive approach should be feasible to better assess both extent and impact of soil degradation interlinking various scales, based on production ecological approaches and remote sensing to allow disentangling natural and human induced causes of degradation. A shared common knowledge base cataloguing hard-won location-specific interventions is needed for successfully preventing or mitigating degradation.
The study was prompted by concerns that soil compaction in horticultural fields at the University... more The study was prompted by concerns that soil compaction in horticultural fields at the University research farm was limiting the performance of fruit trees and vegetable crops after fifteen years of conventional tillage with tractors. Soil penetrometer resistance and bulk density were measured in the profiles of three adjacent fields (vegetable, orchard & vineyard). Over the years, tractor traffic was used in the vegetable field and orchard for seedbed preparation and weeding respectively, while the vineyard was not trafficked. Higher soil compaction was evident in the orchard and vegetable fields compared to vineyard. The location of compacted layers within the profiles was related to the nature of tractor traffic. There was subsoil compaction in the orchard and vegetable fields while shallow compaction was observed in the vineyard. Apart from tractor traffic, low organic matter content and the hardsetting behavior of the soil could have exacerbated the compaction. It was recommended that controlled traffic and deep ripping should be adopted, to not only ameliorate the existing compaction, but also sustain the productivity of the soils.
The use of medicinal plants for contraception remains a common practice among South African ethni... more The use of medicinal plants for contraception remains a common practice among South African ethnic groups. The present study assessed the phytochemical profile, cytotoxicity, acute oral toxicity and efficacy of a herbal mixture used for contraception by the Batswana of South Africa. An aqueous extract was prepared from equal quantities (in terms of weight) of Bulbine frutescens (roots), Helichrysum caespititium (leaves) and Teucrium trifidum (leaves) based on a recipe used by traditional health practitioners. The phytochemical profiles of the freeze-dried herbal mixture were analyzed using gas chromatography–mass spectrometry (GC-MS). In addition, cytotoxicity was determined using an MTT assay on Vero cells and in vivo contraceptive efficacy was evaluated using seven Sprague Dawley rats per control and treatment groups. The control group received distilled water while test groups received 5, 50 and 300 mg/kg of the herbal mixture, which was administered orally once a day for three c...
Animal manure is a key input for soil fertility management among small-scale crop farmers in Sout... more Animal manure is a key input for soil fertility management among small-scale crop farmers in South Africa. However, one of the misgivings that farmers have about the use of fresh animal manure in crop fields is that it encourages growth and proliferation of diverse weed species. Cattle, goat and sheep manure was aerobically composted in windrows over a 10-week period and the emergence and species diversity of weeds were compared with that of un-composted manure. Composting reduced the total number of weeds by an average of 66.3%, 85.1% and 84.2% in cattle, goat and sheep manure, respectively. There were on average six broadleaved weeds to one grass weed emerging in the composted manure. Composting reduced the diversity of weed species by 62% across the three manure types. The highest reduction in species composition was observed in sheep (75%) and goat (67%) manures compared to cattle (40%) manure. There were no grass weed species in the composted goat and sheep manures. The study c...
Cleome gynandra is an African indigenous leafy vegetable that is widely consumed by rural househo... more Cleome gynandra is an African indigenous leafy vegetable that is widely consumed by rural households in South Africa but there is a dearth of information on its cultivation and management. This study was aimed at determining the effects of applying ruminant kraal manure (cattle, goat and control) in combination with harvesting techniques (cutting edible tender tips only, cutting all leaves and cutting all the leaves but once at the end of the growing period) on biomass yield of leaves. Plants were grown in large PVC pots and leaves were cut five times before the final harvest. Application of both cattle and goat manure (50:50 by volume, soil: manure) significantly increased leaf biomass yields compared with the control. Plants that were grown in soil amended with goat manure produced significantly higher total fresh leaf yield (470.86 g pot -1 ) than those under cattle manure (328.42 g pot -1 ). The yields in the treatments with manure increased progressively with each harvesting wh...
African indigenous leafy vegetables have the important role of providing essential minerals, vita... more African indigenous leafy vegetables have the important role of providing essential minerals, vitamins and amino acids in diets of poor smallholder farmer households in sub-Saharan Africa. A study was conducted to quantify the influence of applying cattle and goat manure on the biomass yields and crude protein content of two commonly used African leafy vegetables (Cleome gynandra and Amaranthus hybridus) when subjected to varying leaf cutting management. Treatments for each vegetable consisted of a combination of three manures (control, cattle and goat) and three cutting regimes (cutting edible leaves, all harvestable leaves and cut only at the end) utilised in randomised block design. The results showed significant increase in leaf biomass yields and crude protein content of both vegetables due to manure application. Goat manure was superior to cattle manure due to its higher quality in terms of nutrient content and lower C:N ratio. Cutting the edible leaves more frequently, every f...
In Africa, indigenous methods of contraception continue to play a significant role in preventing ... more In Africa, indigenous methods of contraception continue to play a significant role in preventing unwanted pregnancies despite the introduction and popularity of modern contraceptives. The current review identified the common techniques and practices of African indigenous contraception, and examined their mechanisms and reasons for use. We searched data bases such as Google Scholar, Scopus, Web of Science, EBSCohost, African Journals, Science Direct, textbooks, thesis and dissertations for research articles on African indigenous contraception. The six common techniques of African indigenous contraception included periodic abstinence, withdrawal, breastfeeding, use of herbs, postpartum abstinence and waist bands, whilst practices relate to child (birth) spacing, postponement of first birth (virginity), stopping of reproduction and indigenous emergency contraception. Mother and infant health was stated as one of the reasons for using African indigenous contraception. African indigenous...
The influence of root growth and water regime on the formation of aggregates was studied in modif... more The influence of root growth and water regime on the formation of aggregates was studied in modified minirhizotrons under controlled conditions. Two soils, a black earth (67% clay) and a red-brown earth (19% clay) were ground and forced through a 0.5 mm sieve. Ryegrass, pea and wheat were grown for fifteen wetting and drying (wd) cycles for 5 months. Another set of minirhizotrons was not planted and served as a control. Measurements of aggregate size distribution (ASD), aggregate tensile strength (ATS), aggregate stability (AS), aggregate bulk density (ABD) and organic carbon (OC) were made on single aggregates of the 2–4 mm fraction. The results showed that aggregates of the black earth which has a high clay content and shrink/swell properties had more smaller aggregates with higher ATS, AS and ABD than those from the red-brown earth. It was also found that for both soils: (1) w/d cycles and higher root length density (RLD) increased the proportions of smaller aggregates and aggregate strength; (2) differences in the ability of the plant species to influence aggregation was evident and seemed to be related to the RLD. The RLD was in the order ryegrass > wheat > pea. Mechanisms likely to be involved in processes of aggregate formation and stabilization are discussed. They include cracking of soil due to tensile stresses generated during drying of a shrinking soil; changes in pore water pressure within the soil mass caused by water uptake by plant roots generating effective stresses; and biological processes associated with plant roots and root exudates.
The effects of Aloe ferox, Agave sisalana and Gunnera perpensa on haematological and biochemical ... more The effects of Aloe ferox, Agave sisalana and Gunnera perpensa on haematological and biochemical parameters of village chickens naturally infected with Heterakis gallinarum were evaluated. One hundred and twelve mature village chickens were randomly allotted into 14 groups of 8 chickens. Group 1 and 2 were orally administered 1 mL distilled water for 4 consecutive days and 1 mL mebendazole (once), respectively. Groups 3-6 received 1 mL orally of aqueous leaf extract of A. ferox for 4 consecutive days, groups 7-10 A. sisalana and 11-14 G. perpensa in graded doses of 50, 100, 200 and 400 mg/kg, respectively. Blood was collected into vacutainers in triplicate, from the wing veins on day 0, 7 and 14. Data was analysed using general linear model of statistical analyses system. Chickens offered A. sisalana (200 mg/kg) had highest alanine transaminase (ALT) value (P < 0.05; 7.50 ± 0.406 U/l) on day 0. On day 7 and 14, there was no difference in ALT values (P >0.05). Significant diffe...
A field experiment was conducted to evaluate the influence of root diameter on the ability of roo... more A field experiment was conducted to evaluate the influence of root diameter on the ability of roots of eight plant species to penetrate a compacted subsoil below a tilled layer. The soil was a fine sandy loam red-brown earth with a soil strength of about 3.0 MPa (at water content of 0.13 kg kg-1, corresponding to 0.81 plastic limit) at
Simeon Albert Materechera Crop Science Department, Faculty of Agriculture, Science & Technology, ... more Simeon Albert Materechera Crop Science Department, Faculty of Agriculture, Science & Technology, North-West University (Mafikeng Campus), P/B X2046, Mmabatho, 2735, Republic of South Africa Tel/fax: +27183843806; E-mail: Albert.Materechera@nwu.ac.za ABSTRACT As is the case with many other countries in sub-Saharan Africa, crop production among small scale farmers, especially those in semi-arid regions of South Africa, is hampered by predominance of extreme climate (low, irregular & erratic rainfall), low inherent soil fertility and low use of mineral fertilizers. However, the small scale farmers have developed a range of indigenous knowledge and practices which have played a pivotal role in the management of soil fertility for sustaining crop productivity. This study sought to establish and document these strategies in four farming districts located in semi-arid areas of the country. It was found that farmers use locally adaptable and cost effective strategies including animal manure...
Current Opinion in Environmental Sustainability, 2012
ABSTRACT Continuing soil degradation remains a serious threat to future food security. Yet, globa... more ABSTRACT Continuing soil degradation remains a serious threat to future food security. Yet, global soil degradation assessments are based on qualitative expert judgments or remotely sensed quantitative proxy values that suffice to raise awareness but are too coarse to identify appropriate sustainable land management interventions. Studies in China and Sub Saharan Africa illustrate the considerable impact of degradation on crop production but also point to the need for solutions dependent on location specific agro-ecological conditions and farming systems.The development of a comprehensive approach should be feasible to better assess both extent and impact of soil degradation interlinking various scales, based on production ecological approaches and remote sensing to allow disentangling natural and human induced causes of degradation. A shared common knowledge base cataloguing hard-won location-specific interventions is needed for successfully preventing or mitigating degradation.
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