The evaluation of growth characteristics, biomass yield, and chemical composition of two cultivars of Panicum maximum (Mombaca and Gatton) and Brachiaria brizantha (Marandu) at different harvesting stages
- Authors: Sokupa, Mihle Inga https://orcid.org/0000-0002-3918-1393
- Date: 2020-11
- Subjects: Pastures
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21433 , vital:48621
- Description: The objective of this study was to carry out a comparative assessment of growth characteristics, biomass yield and chemical composition of Panicum maximum and Brachiaria brizantha cultivars at different harvesting stages. The field experiment was conducted at the University of Fort Hare research farm in Alice, South Africa. The main factors were three cultivars: Mombaca, Gatton (Panicum maximum) and Marandu (Brachiaria brizantha) and three harvesting stages (6, 10 and 14 weeks after planting). This study was a 3 × 3 factorial set up in a randomized complete block design with three replicates. Characteristics which included plant height, number of leaves and number of tillers were measured in five plants per plot at 2-week intervals from 4 to 14 weeks after planting (WAP). The fresh yield was weighed then oven dried at 65oC for 72 hours then dry matter yield was calculated after drying. The chemical composition (Ash, Fat, ADF, ADL, NDF, CP, Ca, Mg, Na, P, K, Cu, Fe, Zn and Mn) was determined on forage harvested at 6, 10 and 14WAP. Data was analysed using the Statistical Analysis Software in a 3x3 factorial to compute the ANOVA and all means of all treatments were calculated and the difference was tested for significance using the Least Significant Difference (LSD) test at P=0.05. The results showed variations (P<0.05) in plant height, but the number of leaves did not differ (P > 0.05) between the cultivars. The number of tillers were significantly different (P<0.05), the highest number of tillers was observed in Mombaca. Fresh yield showed significant differences at 10 and 14WAP, with Marandu producing the highest Fresh yield. The moisture content was different (P<0.05) across all the three harvests. Varying (P< 0.05) results were also observed in the dry matter yield of the cultivars with Mombaca producing the highest dry matter yield. There were no significant differences (P>0.05) in the ash content of the cultivars. The fat content also showed no significant differences. Variations (P<0.05) occured in the ADF of the cultivars, Marandu had the lowest ADF. The cultivar × WAP interactive effect was significant for ADL content. NDF significantly varied across the cultivars at 6WAP. There were no similarities (P<0.05) in the crude protein during the three harvesting intervals, Mombaca produced the highest CP and the lowest was obtained from Gatton. There was a significant interaction (P<0.05) between the cultivars and harvesting intervals for Calcium (Ca), Magnesium (Mg), Sodium (Na), Potassium (K), K/Ca+Mg, Copper (Cu), Iron (Fe), Zinc (Zn) and Manganese (Mn) contents of the cultivars. However, Phosphorus (P) showed no significant interaction (P>0.05) between the cultivars and harvesting intervals. The results obtained in this study showed that as the grasses grow, the biomass yield produced increases according to the genetic makeup and the factors affecting growth and biomass yield. However, the chemical composition decreased between cultivars. Mombaca showed superior traits in terms of growth biomass yield and chemical composition. Mombaca, which is a Panicum maximum cultivar can be used as a choice in forage production and chemical composition as it can supply both quality and quantity. It can be concluded that there are significant differences in growth characteristics, biomass yield and chemical composition of Panicum maximum and Brachiaria brizantha cultivars at different harvesting stages. It can also be recommended that the best harvesting stage is at 10 WAP, this is because both biomass yield and chemical composition are both satisfactory. , Thesis (MSc) -- Faculty of Science and Agriculture, 2020
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- Date Issued: 2020-11
Evaluating farmers' perceptions on climate variability and the impact of management practices on rangeland condition at Tukulu Farm, South Africa
- Authors: Huza, Siphamandla
- Date: 2018
- Subjects: Rangelands -- South Africa -- Eastern Cape Range management -- South Africa -- Eastern Cape Livestock -- Breeding -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , Pasture Science
- Identifier: http://hdl.handle.net/10353/10586 , vital:35611
- Description: Rangelands are ecological systems largely used for extensive livestock production, which continually play a vital role in developing the economy of rural communities worldwide. These ecosystems also have the potential to provide vital secondary resources like medicinal plants, firewood and wild foods. This study assessed the impacts of management practices on rangeland condition at Tukulu communal farm in the Eastern Cape province of South Africa. Communal farmers’ perceptions were also investigated on vegetation change and awareness to climate variability. A structured questionnaire with open-ended and closed questions was used to interview communal farmers about several components of their rangeland, their awareness to climate variability and their household demographics were recorded. A rangeland condition assessment with the use of a three-tier system was used to determine vegetation condition and assessment of vegetal change over the past ten to twenty years. Botanical species composition, biomass yield, basal cover, woody plant density, browsing units and soil chemical composition were measured. Tukulu communal rangeland was demarcated into three homogenous vegetation units (HVU) namely, open grassland, scattered bushland and dense bushland. Sample sites of (100×50 m)2 with four replicates were constructed in each HVU. Herbaceous vegetation and basal cover were determined along 100 m transects in each sample site using a step-point method. Aboveground biomass production was estimated using a quadrat system following a systematic sampling by cutting all material within 0.25 m2 quadrats located along 100 m transects. Woody plant density (plants/ha), tree equivalents (TE/ha) and browsing unit (BU/ha) were estimated from the number of woody plants, total woody heights and the number of acceptable and available (<1.5 m) woody species. Soil sample analysis was conducted to determine OC, P, K, N, Ca, Mg, Na, Zn, Cu, and Mn and soil pH in all three HVUs. The respondents consisted of 65 percent males and 35 percent females with an average of about five persons per household. The study revealed that communal farmers at Tukulu were fairly knowledgeable about the changes that have occurred in their rangeland. All respondents 100 percent perceived that their rangeland had changed from good to poor condition. This was characterized by the shift from grass dominance to woody plant encroachment. These changes were linked to the perceived changes in climate. Farmers at Tukulu communal area were generally aware of the changes in climate, 95 percent of the respondents’ perceived changes in weather patterns such as changes in rain seasons, hot weather conditions, unpredictable rainfalls, drought, heavy winds and increased temperatures. The results revealed that Tukulu communal rangeland comprised of high species diversity. Twenty-one herbaceous species and 24 woody species were recorded at Tukulu rangeland. The grass species composition was characterised by 71 percent Increaser II species, 24 percent Decreaser and 5 percent Increaser I species. A highly palatable Decreaser species Themeda triandra decreased in abundance from open grassland to scattered bushland. There were no significant differences (p>0.05) in biomass yield in all three HVUs. However, scattered bushland 761.5 kg/ha and dense bushland 735.8 kg/ha had higher biomass yield when compared to open grassland 688.5 kg/ha. Bush encroachment was observed in dense bushland as the woody plant density 4487.5 trees/ha and tree equivalents 3451.3 trees/ha were significantly (P<0.05) higher than the recommended threshold standards of 2400 trees/ha and 2500 TE/ha. Scattered bushland had tree density of 1900 trees/ha and tree-equivalents of 1534.3 TE/ha. Soil macro and micro nutrients differed significantly between the different HVUs. The levels of Na, Ca, Mg, Cu, Mn differed significantly (p<0.05) between HVUs, increasing from open grassland to dense bushland. Organic carbon concentrations were higher under tree canopies in dense bushland. However, the levels of phosphorus and potassium were higher in open grassland than in the wooded areas. Soil pH in scattered bushland (5.3) and dense bushland (5.18) were significantly higher (p<0.05) than in open grassland (4.89). This study shows complications in management policies governing the Tukulu communal area. There is a need to merge both scientific and indigenous ecological knowledge to ensure the desired outcomes, as this could indeed offer some great insights for communal areas. Therefore, a rangeland rehabilitation programme should be implemented at Tukulu communal rangeland, which will address the issue of bush encroachment and implement a rotational grazing system by fencing camps that will be based on acceptable stocking rates.
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- Date Issued: 2018
Household's perceptions and determinants of participation in harvesting rangeland products :|bthe case of Dyamala community, Raymond Mhlaba Local Municipality, Eastern Cape Province, South Africa
- Authors: Mdiya, Lwandiso
- Date: 2018
- Subjects: Rangelands -- South Africa -- Eastern Cape Communal rangelands -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/9187 , vital:34303
- Description: The study reviews the household’s perceptions and determinants of sustainable products harvesting. Communal rangelands are vast natural landscapes in the form of grasslands, shrubs, woodlands, wetlands and deserts with multiple functions to the rural households. Most rural communities share boundaries and interact with rangelands for multiple socioeconomic and environmental reasons. Since most of these interactions are external to the price mechanism, the actual contribution of rangelands to communities has largely been missed. In an effort to appraise and explore the communal rangeland contribution to households, a study from Dyamala community in the Raymond Mhlaba Local Municipality under Amathole District in Eastern Cape was conducted using cross-sectional data. Descriptive results revealed that the majority of the respondents (71 percent) from the study area positively perceived communal rangelands as safety nets. however, there also emerged a fair share of challenges namely, (bad spirit, host predators, compete with arable land) leading to negative perceptions towards communal rangelands. It was also evident that, the majority of respondents from the study area use communal rangelands for fuel wood, construction poles, traditional medicine, with minor harvests of wild food (flora and fauna) and thatch grass. The results of the study also revealed that, rural people depend more on social grants for their income followed by incomes from remittances, agricultural activities and communal rangelands. However, it was established from the results that though communal rangelands provided commercial products capable of generating household income, rangeland users trading such products were receiving meagre incomes. This might be caused by the lack of institutional support to rural households thus, the low incomes received from communal rangelands. To that effect, main communal rangeland products such as, fuel wood, poles and medicine were cited as being more valuable for local domestic use than for the external market. Regression estimates further indicated that participation in communal rangeland products harvesting is more conditioned by perception-related factors as compared to socioeconomic attributes of rural households worth understanding for strategic targeting to promote their conservation. The extant literature and the study results, evidently show that communal rangelands provide a livelihood among rural households although it has a low direct household income potential. Therefore, the respondents were of the view that the use of campaigns targeting several perceptions (such as communal rangelands act as a source of medicinal plants, arable land and income etc) as suggested by the regression estimates may be very useful. The support from the extension department and further research may be necessary for purposes of quantifying harvestable rangeland products capable of enhancing rural livelihoods. Moreover, the observed low income potential of communal rangeland products suggests several technical and institutional challenges worth addressing to promote value addition of rangeland products.
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- Date Issued: 2018
The effects of rhizobium inoculation on growth performance, forage production, nutrient and anti-nutrient content of lablab purpureus cultivars
- Authors: Senti, Sibongile Portia https://orcid.org/0000-0003-4906-9570
- Date: 2017
- Subjects: Livestock productivity , Rhizobium japonicum
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22864 , vital:53011
- Description: Declining soil fertility and inadequate low quality feed resources limit smallholder livestock production in the semi-arid regions of Eastern Cape in South Africa. Smallholder farmers are facing problems of high cost of artificial fertilisers limiting them in production of cereal crops and also fodder for their livestock. This leads to poor nutrition, particularly in the dry season, it affects livestock production. Planting Lablab purpureus and inoculating with Rhizobium would limit the necessity for buying expensive protein supplements and nitrogen fertilisers. Lablab purpureus can provide feed in the dry season for the improvement of livestock production. The objective of this study was to investigate the effect of Bradyrhizobium japonicum inoculation on growth performance, biomass production, nutrient and anti-nutrient content of the two Lablab purpureus cultivars (Rongai and Highworth). The experiment was conducted at Fort Hare Research Farm in Alice, South Africa. Data was collected on plant seedling emergence, plant height, stem diameter, plant vigour, chlorophyll content, nodule numbers as well as dry matter content, biomass yield, nutrient and anti-nutrient contents at 30, 60 and 90 DAP. Samples of Lablab purpureus were harvested at flowering stage and analysed for dry matter content, biomass yield, chemical, mineral and anti-ntrient composition. The results showed that Rhizobium inoculation significantly increased (p<0.05) seedling emergence, plant height and stem diameter of both Lablab purpureus cultivars. Rhizobium inoculation had no significant effect (p>0.05) on chlorophyll content for both cultivars. Highworth had significantly higher (p<0.05) plant vigour than Rongai on both inoculated and uninoculated. Varieties and inoculation effects were significant (p<0.05) for number of nodules, nodulation rate, active nodules and nodule dry yield. Rhizobium inoculation significantly (p<0.05) increased fresh matter yield, dry matter yied and dry matter content on both cultivars. There were no significant differences (p>0.05) in NDF, ADIN, ADL, ADF, and Na between inoculated and uninoculated plants for both cultivars. The inoculation of Rhizobium improved CP (15.65%) in Highworth cultivar. The inoculation of Rhizobium significantly increased Ca (1.76-1.84%), Zn (191.91-2 8.33ppm) and Cu (3.50-6.16ppm) compared to un-inoculated plants. Varieties and Rhizobium had no interaction (p>0.05) with condensed tannin, hydrolysable tannin, total polyphenols and saponins . Therefore, the Rhizobium inoculation assisted in improving quality in terms of nutrient composition and decreasing anti-nutrients. It is recommended to use both cultivars of Lablab purpureus. Based on the results of this study it is concluded that Rhizobium inoculation increases yield and forage quality of Lablab purpureus. It is recommended that Highworth cultivar can be used by communal farmers in the Eastern Cape. This cultivar showed that it needs Rhizobium inoculation inorder to produce high quality that can increase livestock production. , Thesis (MSc) -- Faculty of Science and Agriculture, 2017
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- Date Issued: 2017
Assessment of rangeland condition and evaluation of farmers' perception in Njwaxa and Mbizana communal rangelands of the Eastern Cape, South Africa
- Authors: Ngcofe, Odwa Armstrong
- Date: 2016
- Subjects: Rangelands -- South Africa -- Eastern Cape Land tenure -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13259 , vital:39627
- Description: This study was conducted to determine of rangeland condition in terms of botanical composition, soil nutrient composition, and also to evaluate farmers’ perception on rangeland condition and degradation in two communal villages Njwaxa and Mbizana in the Eastern Cape Province of South Africa in 2014. A Structured questionnaire consisting of close and open-ended questions was used to investigate farmers’ perceptions on range condition, land degradation, and their causes. Fifty households with livestock were randomly selected in two communal areas of Middledrift (i.e. Njwaxa and Mbizana). Respondents of 21 years and above were selected. For assessment of range condition three homogeneous vegetation units (HVU) were demarcated in all study sites, namely slope; valley and toplands were demarcated and sub-divided into four 100m x 50m replicates. In each replicate, four 100m transects were laid parallel to each other 25m apart 1m2 quadrant was systematically located four times along each transect for herbaceous vegetation and soil sampling. The step point method was employed to determine herbaceous species composition and basal cover. A 400m2 belt transect was used to determine woody vegetation composition, density and tree equivalents in each HVU. The germination method was employed for soil seed bank composition and plant density. The soil micro and macro nutrients (N, P, K OC, Ca, Mg, Zn, Cu and Mn) and pH were also analyzed The majority of the respondents were between the ages of 51-60 years. Most of the farmers had more cattle (38percent) than goats (32percent) and sheep (30percent). Livestock numbers were perceived to have declined over the previous 20 years by the majority of respondents (96percent). The respondents indicated that their rangelands were mainly used for browsing (1.37), fire wood (2.01), building and fencing (2.63) and medical purposes (3.66). All the respondents indicated that their rangelands were highly degraded. Sheet erosion (50percent) was perceived to be the major type of soil erosion indicator mentioned by the farmers, followed by gully erosion (29percent) and rill erosion (21percent). The rangeland was dominated by Increaser II (pioneer) (63.2 percent) grass species followed by Decreaser (mesophytes) species (26.3percent). Digitaria eriantha in the valley (53.5 percent) was significantly higher (p<0.05) than both in the top (10.5percent) and sloppy areas (33.5percent) at Njwaxa communal rangeland, the abundance of D. eriantha was significantly higher (p<0.05) than top and valley in Mbizana communal rangeland. The results showed that soil seed banks were dominated by perennials, followed by annuals and biennial species being least abundant. The dominant forb Jamebrittenia c.f. albanesis was significantly higher (p<0.05) in both slopes (6.65percent) and toplands (7.34percent) than in the valley (3.15). The second most dominant species Puesdognaphalium undulata was significantly higher (p<0.05) in topland areas (6percent) than in valley bottom (3.8percent) and sloppy areas (4.3percent). The results of soil nutrients revealed no significant differences (p>0.05) in the concentration of OC, Ca, and Mg between the communities and seasons. Phosphorus (P) was significantly higher (p<0.05) in winter (concentrations) in most of the sites, except the top sites of Mbizana where summer concentration of P was significantly higher than winter. Potassium (K) was significantly higher (p<0.05) in summer than in winter in most of the HVUs, except the topland areas of Njwaxa and Mbizana sloppy areas where there were no significant differences (p>0.05) in the concentration of K. Soil pH did not display any significant differences (p>0.05) between communities and sites. The mean soil pH recorded in this study was 5.4 implying the soils of Njwaxa and Mbizana communities were acidic. It is evident that communal farmers are well aware of their rangeland condition, changes occurring in their rangelands, their causes and are capable of suggesting some solutions in controlling the declining condition of the rangelands. This study has shown the importance of engaging farmers’ inputs in range assessment since those are people bearing the consequences of rangeland degradation.
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- Date Issued: 2016
Effects of Pteronia incana (Blue bush) invasion on grass biomass production, soil chemical characteristics and peoples' livelihoods in Ngqushwa communal rangelands, Eastern Cape
- Authors: Ntutha, T
- Date: 2016
- Subjects: Invasive plants -- South Africa -- Eastern Cape Shrublands -- South Africa -- Eastern Cape Rangelands -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4682 , vital:28493
- Description: The objective of the study was to assess the farmers’ knowledge and perceptions of P. incana invasion and impacts on rangeland, livestock production and livelihood in four communal grazing areas. Twenty households per village that own livestock were randomly selected to conduct an interview using an open and closed ended questionnaire. In each household, an old and knowledgeable respondent about P. incana invasion was used as a selection criterion. For scientific assessment of range condition, the experiment was conducted in a 270 m x 100 m trial plots that were established in 2014. The area was divided into 3 open and 3 fenced subplots each having an area of 45 m x 100 m established laid down a slope gradient. Each plot was divided into four equal subplots to apply the control treatments. Therefore, the trial layout was a stratified block experiment of four treatments replicated three times. The four control treatments applied to P. incana invasion were chopping and resting (CR), resting without chopping (RWOC), grazing and chopping (GC), grazing without chopping (GWOC). A step point method was applied in each transect to monitor species composition and P. incana cover. On the fenced plots two exclosures of 1mx1m size were randomly distributed to make sure that resting is maintained. Within exclosures 0.25 m2quadrates in each were put randomly to measure biomass. Density of P. incana was determined from 5 m x 5 m quadrates that were placed randomly within each sub-plot. The density and height of individual shrub plant was measured. All rooted live woody plants were recorded and counted in each quadrate. The results revealed that species composition was not affected (P>0.05) by the treatments applied. The herbage height and basal cover had greater values (P<0.05) under rested plus chopping (CR) treatment followed by grazed plus chopping (GC). Grass biomass production and essential nutrients showed a greater concentration (P<0.05) under CR treatment than any treatments applied. The results on perceptions revealed that goats had the highest mean household holding number than any other livestock species across the selected villages in all the villages. Respondents indicated that both goats and cattle had equal or more importance than sheep. Three out of four villages raised cattle primarily for income generation and secondarily for cultural purposes like slaughtering during weddings ceremonies, amazila and also during woman circumcisions (Ntonjane). Similarly, goats and sheep were primarily raised for cash income generation. The results revealed that livestock population decreased over ten to twenty years (one-two decades) and poor rangeland condition is assumed to be the cause of the situation as feed is the key factor for production. The area was dominated by the grasses rather than by browse woody species so the above results are possible as the P. incana is more competitive than grasses. It was concluded that P. incana is detrimental to both rangeland and animal production. Forage and animal performance as well as farmers’ economic status (livelihoods) were negatively affected by P. incana invasion and the scientific assessment reported it to be detrimental to agriculture. Thus chopping and resting (CR) treatment resulted in a greater improvement of the basal cover, biomass production, soil nutrients as well as grass height than the other treatments applied. Therefore it can be concluded that chopping and resting the veld invaded with P. incana can improve the range and consequently animal production.
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- Date Issued: 2016
Evaluating farmers' perceptions and the impact of bush encroachment on herbaceous vegetation and soil nutrients in Sheshegu communal rangelands of the Eastern Cape, South Africa
- Authors: Tokozwayo, Sive
- Date: 2016
- Subjects: Range management -- South Africa -- Eastern Cape Brush -- Control -- South Africa -- Eastern Cape Communal rangelands -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2733 , vital:28066
- Description: Communal rangelands occupy 13 percent of the agricultural land in South Africa, and these rangelands serve as a source of feed to livestock. These areas are threatened by bush encroachment due to poor rangeland management. This study was conducted in Alice (Sheshegu communal area) and the objective was to assess farmers' perceptions and the impact of bush encroachment on herbaceous vegetation and soil nutrients. Structured questionnaires were used to assess indigenous knowledge of communal farmers on the impact of bush encroachment on rangelands. Fourty (40) respondents from households who owned livestock were randomly selected and interviewed at Sheshegu village. About 89 percent of communal farmers perceived that change of their grasslands to encroached savannas was caused by unreliable rainfall, prolonged drought, and poor rangeland management. Rangeland assessment was performed at four sites (Scattered, Moderate, Mixed and Dense bushland. 100mx50m were demarcated per site, and four 100m transects were laid parallel to each other, 30m apart. The step point method was used to determine both species composition and basal cover. Biomass production was determined by harvesting forage within randomly-paced a 0.25m2 quadrats. Aristada congesta and Eragrostis obtuse were the most dominating grass species in dense, mixed and moderate bushland. Scattered bushland was dominated by Themeda triandra. Biomass production increases with increase in bush density and basal cover improved from winter to summer season. Increaser grass species increase with the increase in bush density, this indicated that the rangeland was poorly managed and palatable species were being replaced by less palatable ones. Species composition of woody plants was determined within a 200m2 belt transect in all sites. Maytenus polycantha, Aloe ferox, Erehia rigida and lucas capensis were the most dominant woody species in Mixed bushland while Acacia karroo was most dominated in Scattered, Moderate and Dense bushland. Woody density showed no significant differences (P> 0.05) between Dense, Mixed and Moderate bushland. Woody plant density in all these sites exceed 2500 plants/ha, which showed that the rangeland was encroached with woody plants. Soil nutrient content was determined for each site. Five samples of soil were collected per site to test the effect of bush encroachment on soil nutrient composition. The concentration of nitrogen and soil pH increased with increase in bush density, while that of potassium, phosphorous, magnesium, sodium and sulphur showed no significant differences (P>0.05) across all homogenous vegetation units. The study revealed that Sheshegu communal farmers are aware of both negative and positive effects of encroachment on their community, and also argue that the government is not willing to support communal farmers in the process of reducing the spread of bush encroachment. It was concluded that the concentration of nitrogen and soil pH increased with increasing bush density and that bush encroachment had negative effects on herbaceous species. It was recommended that communal farmers should be formulating rangeland rules and regulations to manage rangeland resources. Rangeland rules and regulations should be based on the management of livestock management during grazing and harvesting of rangeland resources. The harvesting of woody and good timing of application of fire can also reduce the spread of bush encroachment. Veld resting and rotational grazing can also improve fuel load which is required for burning of woody plants. Furthermore, Department of agriculture should also provide workshops or training to communal farmers use different approaches or cheap ways of reducing bush encroachment and conserving rangeland resources.
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- Date Issued: 2016
Woody encroachment and plant-root soil interactions in a semi-arid savanna
- Authors: Gusha, Bukho
- Date: 2015
- Subjects: Pastures -- Management Weeds Invasive plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12139 , vital:39174
- Description: Savannas occupy 1/8 of the global land surface, support a large proportion of the world’s human population and the majority of its rangeland and livestock. Woody encroachment has been reported as the major challenge in these landscapes. This study describes the differences between three contrasting tree density classes in a semi- arid savanna with the view to developing an improved understanding of woody encroachment which is prevalent in this region. The study attempted to determine if there was a relationship between lateral root distributions at varying soil depths with increasing levels of woody encroachment, and to compare species composition and soil water profiles in these rangelands. Three homogeneous vegetation units, namely: sparsely encroached (HVU1), grassland (HVU2) and Albany thicket (HVU3) were identified for the study sites. A Trench method was used determine root biomass and a step point method was used to determine herbaceous species composition in all the HVUs. The results showed that more Decreaser species (especially Themeda triandra) were recorded in a sparsely encroached site (HVU1) and grassland site (HVU2), while Cynodon dactylon was mostly recorded in the thicket site (HVU3). Acacia karroo was mostly recorded in HVU1 while in HVU2 other woody species such as Coddia rudis and Grewia occidentalis were also recoded. HVU3 had the poorest basal cover (point to tuft distance) (22.60 cm) while HVU1 (9.93 cm) and HVU2 (7.73 cm) had moderate basal cover. The herbaceous standing biomass was significantly different across the HVUs. HVU3 was higher (1206.15 kg ha-1) than HVU1 (942.43 kg ha-1) and HVU2 (677.10 kg ha-1). The soil moisture content was significantly different between the HVUs, but was not significantly different between the depths (p< 0.05). High soil moisture content was recorded in HVU3 compared to other HVUs. The results of Analysis of Variance (ANOVA) showed that soil depth and the type of homogenous vegetation unit (HVU) had significant effects (p<0.01) on root biomass. The pair wise t-test showed that there were no significant difference in root biomass between sparsely encroached (HVU1) and grassland (HVU2) sites (p>0.05), but there were significant differences in root biomass between grassland (HVU2) and thicket (HVU3) site (p<0.05). The mean for total root biomass found in the study was 2.66 kg m-2. In all the trenches most of the root biomass was found in depth 1 (0-30 cm) which was 2.43 kg m-2followed by 1.32 kg m-2 in depth 2 (30-60 cm) and 0.49 kg m-2 in depth 3 (60-90 cm). According to the results on species composition, herbaceous biomass, basal cover, soil moisture content and the root biomass, Kwezana communal rangeland has a potential of running a sustainable livestock production enterprise if proper management practices can be implemented. To improve the rangelands of Kwezana communal rangelands, management such as proper resting, burning, proper stocking rates and physically clearing of bushes should be considered.
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- Date Issued: 2015
Woody encroachment and plant-root soil interactions in a semi-arid savanna
- Authors: Gusha, Bukho
- Date: 2015
- Subjects: Pastures -- Management Weeds Invasive plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12053 , vital:39131
- Description: Savannas occupy 1/8 of the global land surface, support a large proportion of the world’s human population and the majority of its rangeland and livestock. Woody encroachment has been reported as the major challenge in these landscapes. This study describes the differences between three contrasting tree density classes in a semi- arid savanna with the view to developing an improved understanding of woody encroachment which is prevalent in this region. The study attempted to determine if there was a relationship between lateral root distributions at varying soil depths with increasing levels of woody encroachment, and to compare species composition and soil water profiles in these rangelands. Three homogeneous vegetation units, namely: sparsely encroached (HVU1), grassland (HVU2) and Albany thicket (HVU3) were identified for the study sites. A Trench method was used determine root biomass and a step point method was used to determine herbaceousspecies composition in all the HVUs. The results showed that more Decreaser species (especially Themeda triandra) were recorded in a sparsely encroached site (HVU1) and grassland site (HVU2), while Cynodon dactylon was mostly recorded in the thicket site (HVU3). Acacia karroo was mostly recorded in HVU1 while in HVU2 other woody species such as Coddia rudis and Grewia occidentalis were also recoded. HVU3 had the poorest basal cover (point to tuft distance) (22.60 cm) while HVU1 (9.93 cm) and HVU2 (7.73 cm) had moderate basal cover. The herbaceous standing biomass was significantly different across the HVUs. HVU3 was higher (1206.15 kg ha-1) than HVU1 (942.43 kg ha-1) and HVU2 (677.10 kg ha-1). The soil moisture content was significantly different between the HVUs, but was not significantly different between the depths (p< 0.05). High soil moisture content was recorded in HVU3 compared to other HVUs. The results of Analysis of Variance (ANOVA) showed that soil depth and the type of homogenous vegetation unit (HVU) had significant effects (p<0.01) on root biomass. The pair wise t-test showed that there were no significant difference in root biomass between sparsely encroached (HVU1) and grassland (HVU2) sites (p>0.05), but there were significant differences in root biomass between grassland (HVU2) and thicket (HVU3) site (p<0.05). The mean for total root biomass found in the study was 2.66 kg m-2. In all the trenches most of the root biomass was found in depth 1 (0-30 cm) which was 2.43 kg m-2followed by 1.32 kg m-2 in depth 2 (30-60 cm) and 0.49 kg m-2 in depth 3 (60-90 cm). According to the results on species composition, herbaceous biomass, basal cover, soil moisture content and the root biomass, Kwezana communal rangeland has a potential of running a sustainable livestock production enterprise if proper management practices can be implemented. To improve the rangelands of Kwezana communal rangelands management such as proper resting, burning, proper stocking rates and physically clearing of bushes should be considered.
- Full Text:
- Date Issued: 2015
Evaluation of range condition, soil properties, seed banks and farmer's perceptions in Peddie communal rangeland of the Eastern Cape, South Africa
- Authors: Mndela, Mthunzi
- Date: 2013
- Subjects: Rangelands -- South Africa -- Eastern Cape , Land tenure -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Forage , Range management -- South Africa -- Eastern Cape , Nguni cattle -- South Africa -- Eastern Cape , Soil seed banks -- South Africa -- Eastern Cape , Ethnoscience -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Pasture Science)
- Identifier: vital:11583 , http://hdl.handle.net/10353/d1013153 , Rangelands -- South Africa -- Eastern Cape , Land tenure -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Forage , Range management -- South Africa -- Eastern Cape , Nguni cattle -- South Africa -- Eastern Cape , Soil seed banks -- South Africa -- Eastern Cape , Ethnoscience -- South Africa -- Eastern Cape
- Description: South African rangelands in combination with their surrounding homesteads occupy 13% of the entire land surface in South Africa. These rangelands are a source of forage for communal livestock. The rangelands in communal tenure system are degraded due to high human population and livestock numbers. The rangeland of Peddie was never evaluated since the introduction of Nguni Cattle Empowerment Project. Therefore, socio-ecological evaluation was conducted in order to interlink farmer‟s perceptions and scientific data to recommend appropriate rangeland management and restoration programme. Two structured questionnaires consisting of close and open ended questions were used to investigate farmer‟s perceptions on rangeland condition, dynamics, and their causes. Sixty households were randomly selected on the bases of livestock ownership and the membership in Nguni Cattle Project. In each household, any respondent of 20 years or greater, and a key informant of age greater than 40 years were selected. For scientific assessment of range condition, three homogenous vegetation units namely grassland, scattered and dense bushland were demarcated into four 100m x 50m replicates. In each replicate, two 100m transects were laid parallel to each other with 30m equidistant apart. The step point and harvesting method along each transect were employed for herbaceous species composition and biomass production. The point-to-tuft distance was also determined as a proxy for basal cover. Woody density, species composition and tree equivalents were determined in 200m2 belt transects in each HVU replicates. The germination method for soil seed bank evaluation was also employed to find plant species composition and density. The soil nutrients (OC, N, P, K, Na, Ca, Mg, Zn, Cu and Mn) and pH were analysed through solution preparation and observation under photospectrometer to determine functional capacity of the soil of Peddie rangeland. The farmer‟s perceptions comprised of 63% females and 37% males (n = 120) with a mean household of 8 people, 5 adults and 3 children. It was perceived by 93.3% respondents that the rangeland of Peddie have undergone changes over two decades. These changes were perceived by 83% respondents to be accompanied by decline in livestock numbers. Woody encroachment and overgrazing were perceived to be the major attributes of these vegetation changes. The scientific rangeland condition assessment confirmed that these changes were more pronounced as bush density increases. Dense bushland had a significantly high (p<0.05) encroached condition with 6650 trees ha-1 and 4909.5 TE ha-1 beyond the recommended thresholds of 2400 trees ha-1 and 2500 TE ha-1 respectively. Scattered bushland had a fair condition of 1950 trees ha-1 and 1198.1TE ha-1. Themeda triandra as a key species was significantly higher (p<0.05) in grassland (31.1%) than scattered (15.6%) and dense bushland (6.1%). There was a declining trend in biomass production from grassland to dense bushland. The summer biomass production was significantly higher (p<0.05) in grassland than scattered and dense bushland but winter biomass was not significantly different (p>0.05) from all homogenous vegetation units of Peddie rangeland. However, the soil fertility increased with an increase in bush density except organic carbon (OC) which was 1.61% in grassland, 1.46% in scattered and 1.53% in dense bushland respectively. Soil N, K, P, Mg2+ Na+, Ca2+, Cu, Zn, Mn and pH were significantly higher (p<0.05) in dense bushland than grassland and scattered bushland. High soil fertility in dense bushland may be attributed to by abscission of woody plants and litter decomposition. In the soil seed bank, the abundances of forbs were significantly higher than sedges (χ2 = 12, df = 1, p = 0.001) and grasses (χ2 = 8.333, df = 1, p = 0.004) in all homogenous vegetation units while sedges were not significantly different (χ2 = 3, df = 1, p = 0.083) from grasses. The Sorensen‟s index indicated that soil seed bank and extant vegetation were significantly different (p<0.05). Annual and biennial forbs and sedges had high abundances while perennial grasses formed a bulk in above ground vegetation. This provided an insight that a reliance on soil seed bank for restoration of Peddie rangeland would not be advisable because it can result in retrogression. The communal rangeland assessment provided clear qualitative and quantitative data when the combination of indigenous knowledge and scientific assessments was done. The rationale is that conclusions and recommendations of range assessment are relient on the farmer‟s perceptions pertinent to their livestock production systems and their rangeland management objectives. This study has shown that inclusion of communal farmers in policy making can provide better insight because those are the people experiencing the consequences of range degradation.
- Full Text:
- Date Issued: 2013
Vegetation and soil characteristics around water points under three land management systems in semi-arid rangelands of the Eastern Cape, South Africa
- Authors: Simanga, Siyabulela
- Date: 2013
- Subjects: Livestock -- Effect of water quality on -- South Africa -- Eastern Cape , Biodiversity conservation -- South Africa -- Eastern Cape , Range ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Pasture Science)
- Identifier: vital:11584 , http://hdl.handle.net/10353/d1015795 , Livestock -- Effect of water quality on -- South Africa -- Eastern Cape , Biodiversity conservation -- South Africa -- Eastern Cape , Range ecology -- South Africa -- Eastern Cape
- Description: This study investigated the vegetation and soil characteristics in relation to distance from water points under different land management systems in semi-arid rangelands of South Africa. Six study sites, two each from communal grazing, commercial farming and game reserves were selected. Two watering points were selected in each study site. Two 500 m transects were laid from the selected watering points. Each transect was divided into sub-transects at 25 m, 50m, 100m, 200m, 300m and 500m from water points. A 100 m2 plot was marked in each sub-transect to record grass biomas, species composition, structure and distribution of woody vegetation and physical and chemical soil properties. Data were collected for two seasons 2012/13 (winter and summer). Thirty and 41 grass and woody species respectively were identified in all study areas. The most common and dominating grass species include Cynodon dactylon, Digitaria eriantha, Eragrostis obtusa, Setaria sphacelata and Sporobolus fimbriatus. Cynodon dactylon and S. sphacelata occurred more abundantly (p < 0.05) in the game reserves than in the other land management catergories. All the grass species had similar (p > 0.05) abundance along distance gradient from water points. Grass dry matter (GDM) showed significant differences (p < 0.05) between and within land management systems. However, GDM was not significantly affected by season, location of water point within each farm or reserve and distance along water points. Acacia karoo, Coddia rudis and Ehretia rigida were the most dominant woody species. Tree equivalent (TE) density of all encroaching woody plants combined was significantly (p < 0.05) higher on the communal area (1732 TE ha-1) than the commercial ranches (1136 TE ha-1) and game reserves (857 TE ha-1), but with no marked variations along distance from water points under all the land management systems. The electric conductivity (EC) was significantly (P < 0.01) higher in game reserves than in communal grazing areas and ranches. Soil organic matter percentage showed greatest and lowest values in the game reserves and commercial respectively. Soil pH and bulk density did not vary but soil organic matter (SOM), EC, bulk density and soil compaction were significant different with no increasing or decreasing trends. Soil properties were affected by herbivore pressure and trampling around water points with inconsistence magnitude and direction. In conclusion, grass species composition and GDM did not respond to distance from water points because either grazing gradient was absent or the length of transects was not enough to explain the absence or presence of gradients. High proportion of A. karoo and high densities of seedlings and saplings would seem as very good indicators of the woody vegetation changes in the different land management systems and distance from water points. The soil quality indicators around the water-points showed that livestock and game affected soil parameters.
- Full Text:
- Date Issued: 2013
Evaluating long term effects of fire frequency on soil seed bank composition and species diversity in a semi-arid , South African savanna
- Authors: Mabuza, Thembisile Veronicah
- Date: 2011
- Subjects: Pastures -- South Africa -- Eastern Cape , Fire management -- South Africa -- Eastern Cape , Forage plants -- Evaluation , Ruminants -- Feeding and feeds , Ruminants -- Nutrition , Soil seed banks
- Language: English
- Type: Thesis , Masters , MSc Agric (Pasture Science)
- Identifier: vital:11579 , http://hdl.handle.net/10353/346 , Pastures -- South Africa -- Eastern Cape , Fire management -- South Africa -- Eastern Cape , Forage plants -- Evaluation , Ruminants -- Feeding and feeds , Ruminants -- Nutrition , Soil seed banks
- Description: Fire is generally used as a management tool for different vegetation types such as savannas and grasslands in southern Africa. In the False Thornveld of the Eastern Cape, fire is commonly used to control bush encroachment and to increase grass production, as grasses are important source of forage for domestic livestock. At the University of Fort Hare farm in the Eastern Cape, a trial was set up in 1980 to investigate the effect of burning frequency on vegetation. There are six treatments replicated twice in a completely randomized design on a 100 m x 50 m plots. The treatments comprise no burn, annual, biennial, triennial, quadrennial and sexennial burns. From this trial a study was conducted to investigate long term effect of burning frequency on species and soil seed bank diversity. Two 100 m line transects located 25 m apart were laid within each plot, and the herbaceous and woody species were identified and recorded along the line transects. Relative abundances (%) for each species were calculated for each treatment. Soil samples were collected at an interval of 13.3 m along the line transects. The samples were placed in paper bags and kept for use in a germination experiment. The seedling emergence germination method was used in the glasshouse to determine emerging seedlings, pots were filled with Hygromix growth medium and the soils from the fire trials 12 X 6 = 72 were spread on top. Soil from the control plots were also pre-treated with heat, smoke and the combination of heat and smoke. The experiment started in January 2010 and was terminated in April 2010. The Shannon-Weaver Diversity Index was used to determine species diversity for standing vegetation and germinated seedlings. Data were tested for normality and species abundances were transformed. Analysis of Variance (ANOVA) was applied to test treatment effects on geminated seedlings, species abundance and diversity at α = 0.05 significance level. Significant differences between treatment means were determined by post v hoc tests using Fischer‟s Least Significant Difference test at α = 0.05. The Pearson Moment Correlation test was used to test the relationship between vegetation and soil seed banks. Treatments had significant effects on herbaceous, woody species abundance and diversity (P < 0.05), but there was no significant treatment effect on soil seed bank diversity and on pre-germination treatments (P > 0.05). The annual, biennial and triennial burns were dominated by Themeda triandra while the quadrennial, sexennial and the control treatments were dominated by Sporobolus fimbriatus and Melica decumbens. A. karroo dominated the woody component across all treatments, but it did not change in abundance. S. fimbriatus was the most abundant in the soil seed bank across all the treatments and also in all pre-germination treatments. Species diversity was high in standing vegetation in the quadrennial, sexennial and the control treatments. There was no significant correlation between the standing vegetation and soil seed bank diversities (P > 0.05). Based on these findings it is apparent that fire can change vegetation in an area to be dominated by fire tolerant or fire intolerant species. Fire frequency, heat and smoke affects soil seed banks to a lesser extent in the False Thornveld. For the management of the False Thornveld of the Eastern Cape, less frequent burning is recommended as it increases aboveground species diversity.
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- Date Issued: 2011