Perceptions of rural households about the role and effect of biogas production on rural household income in Raymond Mhlaba Local Municipality
- Authors: Ngcobo, Lindiwe
- Date: 2017
- Subjects: Biomass energy -- South Africa -- Eastern Cape Renewable energy sources -- South Africa -- Eastern Cape Sustainable living -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4694 , vital:28494
- Description: Rural development efforts to reduce poverty and enhance food security and generally improve livelihoods in developing countries continue to be constrained by high energy cost. For that reason, renewable energy has been identified as a possible panacea to fill this gap. Renewable energy is cheaper, more accessible and environmentally sustainable and promotes inclusivity. Biogas is a renewable energy that is readily available and easy to use by poor rural households. The use of biogas digesters among households in rural areas of developing countries is a well-known technology. The potential for biogas in these areas has been demonstrated and a strong economic case has been made. However, its adoption and use have been lower than expectations possibly as result of non-economic considerations, including social issues about which rural people hold different perceptions. Perceptions of rural households are important because they influence the behaviour to a large extent. Since limited access to affordable energy in rural areas has encouraged government and private organisations to initiate biogas projects to overcome the challenge, it is important to ascertain the factors that affect attitudes towards the technology. The present study sought to explore perceptions of rural households about biogas production towards rural household income in the Raymond Mhlaba Local Municipality. Specifically, this research investigated the state of biogas project being implemented by the University of Fort Hare’s Institute of Technology (FHIT), the perceptions of respondents towards biogas production and determine the contribution of biogas consumption to rural income. The study also aimed to identify the factors affecting the adoption of biogas production in the study area. The study was carried out in Melani village in Raymond Mhlaba Local Municipality in the Eastern Cape Province of South Africa and employed survey data obtained from 48 households who were enumerated to identify their perceptions on biogas production, with special emphasis on the role and effect contributed to rural income of Melani village. The study employed a cross-sectional research design and purposive sampling technique was used in data collection. Data were collected and captured in Excel and then analysed using the statistical package for social sciences (SPSS) Version 24 Descriptive statistics was used to examine socio-economic characteristics of households and state of biogas production in the area, Bivariate correlation analysis was used to determine the relationships among the key elements of perceptions of household towards biogas adoption, binary logistic model was used to estimate factors influencing adoption of biogas technology by households. The results show that women were dominant for both adopters and non-adopters of biogas. The majority of households were young with mean age of 40 years while for non-adopters were 65 years old on average. The results showed high levels of literacy amongst household adopters. Majority of the households for both adopters and non-adopters of biogas technology were married and unemployed and household size ranged from one to five persons, with social grants being dominant source of income. The bivariate correlation analysis suggests a positive effect of green pepper production and livestock ownership on biogas technology adoption. Age and level of education were negatively correlated with adoption of biogas. The cross tabulation analysis suggests that water scarcity, lack of knowledge about biogas technology, cattle ownership, lack of maintenance and repairing, flooded biogas digesters during rainy season are negatively associated with the uptake of biogas technology. The empirical results from binary logistic model suggest that land size was the key determinant of adoption behaviour towards biogas technology while age of the household head, source of income and level of education may have a negative influence on adoption of biogas technology. Based on the findings highlighted above, the study recommends strategies to encourage households to adopt biogas technology.
- Full Text:
- Date Issued: 2017
- Authors: Ngcobo, Lindiwe
- Date: 2017
- Subjects: Biomass energy -- South Africa -- Eastern Cape Renewable energy sources -- South Africa -- Eastern Cape Sustainable living -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4694 , vital:28494
- Description: Rural development efforts to reduce poverty and enhance food security and generally improve livelihoods in developing countries continue to be constrained by high energy cost. For that reason, renewable energy has been identified as a possible panacea to fill this gap. Renewable energy is cheaper, more accessible and environmentally sustainable and promotes inclusivity. Biogas is a renewable energy that is readily available and easy to use by poor rural households. The use of biogas digesters among households in rural areas of developing countries is a well-known technology. The potential for biogas in these areas has been demonstrated and a strong economic case has been made. However, its adoption and use have been lower than expectations possibly as result of non-economic considerations, including social issues about which rural people hold different perceptions. Perceptions of rural households are important because they influence the behaviour to a large extent. Since limited access to affordable energy in rural areas has encouraged government and private organisations to initiate biogas projects to overcome the challenge, it is important to ascertain the factors that affect attitudes towards the technology. The present study sought to explore perceptions of rural households about biogas production towards rural household income in the Raymond Mhlaba Local Municipality. Specifically, this research investigated the state of biogas project being implemented by the University of Fort Hare’s Institute of Technology (FHIT), the perceptions of respondents towards biogas production and determine the contribution of biogas consumption to rural income. The study also aimed to identify the factors affecting the adoption of biogas production in the study area. The study was carried out in Melani village in Raymond Mhlaba Local Municipality in the Eastern Cape Province of South Africa and employed survey data obtained from 48 households who were enumerated to identify their perceptions on biogas production, with special emphasis on the role and effect contributed to rural income of Melani village. The study employed a cross-sectional research design and purposive sampling technique was used in data collection. Data were collected and captured in Excel and then analysed using the statistical package for social sciences (SPSS) Version 24 Descriptive statistics was used to examine socio-economic characteristics of households and state of biogas production in the area, Bivariate correlation analysis was used to determine the relationships among the key elements of perceptions of household towards biogas adoption, binary logistic model was used to estimate factors influencing adoption of biogas technology by households. The results show that women were dominant for both adopters and non-adopters of biogas. The majority of households were young with mean age of 40 years while for non-adopters were 65 years old on average. The results showed high levels of literacy amongst household adopters. Majority of the households for both adopters and non-adopters of biogas technology were married and unemployed and household size ranged from one to five persons, with social grants being dominant source of income. The bivariate correlation analysis suggests a positive effect of green pepper production and livestock ownership on biogas technology adoption. Age and level of education were negatively correlated with adoption of biogas. The cross tabulation analysis suggests that water scarcity, lack of knowledge about biogas technology, cattle ownership, lack of maintenance and repairing, flooded biogas digesters during rainy season are negatively associated with the uptake of biogas technology. The empirical results from binary logistic model suggest that land size was the key determinant of adoption behaviour towards biogas technology while age of the household head, source of income and level of education may have a negative influence on adoption of biogas technology. Based on the findings highlighted above, the study recommends strategies to encourage households to adopt biogas technology.
- Full Text:
- Date Issued: 2017
Performance of a residential swimming pool air source heat pump water heater installed in Fort Beaufort, South Africa
- Authors: Mqayi, Singatha
- Date: 2017
- Subjects: Water heaters Heat pumps Swimming pools -- Heating and ventilation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4835 , vital:28532
- Description: Globally, there is growing concern about energy consumption and its diverse effects on the environment. In South Africa, the current status quo is unfavourable in the domain of energy, hence the Department of Energy, Eskom and NERSA have embarked on supporting energy efficiency technologies nationwide as a strategic goal in reducing demand on the national grid. Due to the non conservative consumption of electricity from the grid and the insufficient supply to meet its demand, the importation of crude oil is very certain. In addition, the current and most popular technology for pool water heating in the said country is the resistive element which is inefficient and non-cost-effective. The energy consumption of residential swimming pool water heating is very massive, and tariff structure shows a constant rise. Furthermore, there's a current electricity crisis during the Eskom evening peak. Hence, a reliable, efficient, cost-effective and renewable energy technology such as an air source heat pump is required as a retrofit to the existing resistive element. Furthermore, mathematical modelling is a tool that can be used to mimic the dynamic behaviour of a physical or process system. It is a computational language or mathematical equation used to predict the dynamic behaviour of physical systems [Tangwe et al., 2015]. Various methods such as numerical methods have been considered as the particular types of mathematical modelling which have been employed to predict the performance of swimming pool ASHP water heater. However, they were unreliable and expensive. Consequently, this research focused on the experimental determination of the viability and development of a mathematical model to predict the performance of swimming pool ASHP water heater. The benefit of the development and building of this model was attributed to its low cost and credibility to forecast the performance of swimming pool ASHP water heater. Also, this robust mathematical model can be used by an energy service company and system manufacturer to compute the dynamic coefficient of performance of the swimming pool ASHP water heater. Following the above-mentioned information, the research sought to provide a permanent solution to the Eskom evening peak constraint. This is because energy-efficiency, serves as the bridging block between conventional and renewable energy sources needed by Eskom in a bid to provide a balance energy mix and sustainable energy. The implementation of a swimming pool ASHP water heater guaranteed a conducive environment for the population due to the reduction in environmental pollution.
- Full Text:
- Date Issued: 2017
- Authors: Mqayi, Singatha
- Date: 2017
- Subjects: Water heaters Heat pumps Swimming pools -- Heating and ventilation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4835 , vital:28532
- Description: Globally, there is growing concern about energy consumption and its diverse effects on the environment. In South Africa, the current status quo is unfavourable in the domain of energy, hence the Department of Energy, Eskom and NERSA have embarked on supporting energy efficiency technologies nationwide as a strategic goal in reducing demand on the national grid. Due to the non conservative consumption of electricity from the grid and the insufficient supply to meet its demand, the importation of crude oil is very certain. In addition, the current and most popular technology for pool water heating in the said country is the resistive element which is inefficient and non-cost-effective. The energy consumption of residential swimming pool water heating is very massive, and tariff structure shows a constant rise. Furthermore, there's a current electricity crisis during the Eskom evening peak. Hence, a reliable, efficient, cost-effective and renewable energy technology such as an air source heat pump is required as a retrofit to the existing resistive element. Furthermore, mathematical modelling is a tool that can be used to mimic the dynamic behaviour of a physical or process system. It is a computational language or mathematical equation used to predict the dynamic behaviour of physical systems [Tangwe et al., 2015]. Various methods such as numerical methods have been considered as the particular types of mathematical modelling which have been employed to predict the performance of swimming pool ASHP water heater. However, they were unreliable and expensive. Consequently, this research focused on the experimental determination of the viability and development of a mathematical model to predict the performance of swimming pool ASHP water heater. The benefit of the development and building of this model was attributed to its low cost and credibility to forecast the performance of swimming pool ASHP water heater. Also, this robust mathematical model can be used by an energy service company and system manufacturer to compute the dynamic coefficient of performance of the swimming pool ASHP water heater. Following the above-mentioned information, the research sought to provide a permanent solution to the Eskom evening peak constraint. This is because energy-efficiency, serves as the bridging block between conventional and renewable energy sources needed by Eskom in a bid to provide a balance energy mix and sustainable energy. The implementation of a swimming pool ASHP water heater guaranteed a conducive environment for the population due to the reduction in environmental pollution.
- Full Text:
- Date Issued: 2017
Socio-economic benefits of agricultural projects to surrounding communities: the case of Qamata Irrigation Scheme in the Eastern Cape, South Africa
- Authors: Masela, Zandile
- Date: 2017
- Subjects: Agricultural development projects -- South Africa -- Eastern Cape , Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Irrigation farming -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4716 , vital:28501
- Description: The Qamata Irrigation Scheme (QIS) is one of the largest irrigation schemes in South Africa. Despite substantial state investment, community members have only derived limited benefits from the scheme, leading the government efforts to revitalize the scheme. Many studies have been conducted about QIS but none of them have analyzed the effects of the QIS on the surrounding communities. This study investigated the socio-economic benefits of QIS to surrounding communities. For the purposes of this study, the units of analysis were the surrounding household members, questionnaires were used to collect data. Probabilistic sampling of random sampling method was used to select the villages; respondents’ were availability selected with sample size of 197 households. Quantitative and qualitative data were collected from the participants. To analyse data, descriptive statistics and multinomial logit regression model were used. The study found out that female-headed households constitute 63.45 percent compared to male-headed households at 36.55 percent. The average age of the households in the villages that are within the radius of 10km is 58 years, while it is 59 years in villages that are beyond the 10km radius. In villages within the radius of 10km, 86.08 percent of respondents are unemployed, 5.70 percent are employed at the scheme and 8.23 percent are self-employed. In villages beyond 10km, 84.62 percent of respondents are unemployed, 5.13 percent are employed at the scheme and 10.26 percent are self-employed. In both villages, 71 percent of respondents reported that that they do not get feed supply from the scheme while 29 percent of respondents reported that they get feed supply from the scheme. From the overall distribution of villages within and beyond the radius of 10km, 80 percent of respondents reported that they do not get job opportunities from the QIS while 20 percent of respondents reported that they get job opportunities from the QIS. The study shows that 53 percent of respondents from villages within the radius of 10km are low-benefitting, 33 percent of respondents are intermediate-benefitting and 14 percent of respondents are high-benefitting from the scheme, while in villages beyond the radius of 10km, 97 percent of respondents are low-benefitting, 3 percent of respondents are intermediate-benefitting and none of the respondents is high-benefitting from the scheme. Furthermore, the study, through the multinomial logit regression model, shows that gender for intermediate benefitting has a negative coefficient (-1.70) and shows a significance of 10 percent On the other hand, gender for high benefitting has a positive coefficient (2.57) and shows a significance of 1 percent. Distance from the scheme has a negative coefficient (-3.08) and shows a significance of 1 percent. Access to farmland has a positive coefficient (2.33) and shows a significance of 10 percent. The study recommends that surrounding communities should own home gardens so that they can grow fresh produce and create job opportunities. The surrounding communities are also encouraged to own more farmlands or produce their own crops so they can also learn from the skills of the scheme.
- Full Text:
- Date Issued: 2017
- Authors: Masela, Zandile
- Date: 2017
- Subjects: Agricultural development projects -- South Africa -- Eastern Cape , Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Irrigation farming -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4716 , vital:28501
- Description: The Qamata Irrigation Scheme (QIS) is one of the largest irrigation schemes in South Africa. Despite substantial state investment, community members have only derived limited benefits from the scheme, leading the government efforts to revitalize the scheme. Many studies have been conducted about QIS but none of them have analyzed the effects of the QIS on the surrounding communities. This study investigated the socio-economic benefits of QIS to surrounding communities. For the purposes of this study, the units of analysis were the surrounding household members, questionnaires were used to collect data. Probabilistic sampling of random sampling method was used to select the villages; respondents’ were availability selected with sample size of 197 households. Quantitative and qualitative data were collected from the participants. To analyse data, descriptive statistics and multinomial logit regression model were used. The study found out that female-headed households constitute 63.45 percent compared to male-headed households at 36.55 percent. The average age of the households in the villages that are within the radius of 10km is 58 years, while it is 59 years in villages that are beyond the 10km radius. In villages within the radius of 10km, 86.08 percent of respondents are unemployed, 5.70 percent are employed at the scheme and 8.23 percent are self-employed. In villages beyond 10km, 84.62 percent of respondents are unemployed, 5.13 percent are employed at the scheme and 10.26 percent are self-employed. In both villages, 71 percent of respondents reported that that they do not get feed supply from the scheme while 29 percent of respondents reported that they get feed supply from the scheme. From the overall distribution of villages within and beyond the radius of 10km, 80 percent of respondents reported that they do not get job opportunities from the QIS while 20 percent of respondents reported that they get job opportunities from the QIS. The study shows that 53 percent of respondents from villages within the radius of 10km are low-benefitting, 33 percent of respondents are intermediate-benefitting and 14 percent of respondents are high-benefitting from the scheme, while in villages beyond the radius of 10km, 97 percent of respondents are low-benefitting, 3 percent of respondents are intermediate-benefitting and none of the respondents is high-benefitting from the scheme. Furthermore, the study, through the multinomial logit regression model, shows that gender for intermediate benefitting has a negative coefficient (-1.70) and shows a significance of 10 percent On the other hand, gender for high benefitting has a positive coefficient (2.57) and shows a significance of 1 percent. Distance from the scheme has a negative coefficient (-3.08) and shows a significance of 1 percent. Access to farmland has a positive coefficient (2.33) and shows a significance of 10 percent. The study recommends that surrounding communities should own home gardens so that they can grow fresh produce and create job opportunities. The surrounding communities are also encouraged to own more farmlands or produce their own crops so they can also learn from the skills of the scheme.
- Full Text:
- Date Issued: 2017
Thermodynamic and electrical performance monitoring of a domestic split-type air conditioner and development of a simulation based R22 permanent replacement
- Authors: Bantan, Mafor Glory
- Date: 2017
- Subjects: Air conditioning
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4857 , vital:28537
- Description: The difficulty that exists in accurately monitoring the performance of air conditioners has made performance prediction an arduous task. Nevertheless, the performance still needs to be monitored and predicted as it helps solve a lot of problems resulting from this technology like effect of the technology on the grid, energy consumption, water utilisation and GHGs emission. With the introduction of regression modelling as a means of system monitoring and prediction some years ago, the accuracy was still a call for concern. It is worth realising that increasing the number of predictors will enhance this method’s accuracy. As such, this document intends to increase the accuracy of this method’s monitoring and predicting ability by increasing the number of predictors to cut across system thermal, environmental and human behavioural variation. These predictors experimentally gotten are used to build an environ-behavioural model that monitors the coefficient of performance and energy consumption of a domestic split-type air conditioner with higher accuracy. Refrigerants have undergone evolution in the past decades in a bid to come up with a refrigerant that has zero ODP, lower – than – R22 GWP and much better than R22 thermodynamic performance. No pure refrigerant has been found to possess these qualities as such mixtures or blends are the best shot at the moment. R410A could stand the test of time to be the long term R22 replacement but for the fact that besides R410A’s higher GWP than that of R22, the former’s system performance is lower than that of the latter’s due to the lower thermodynamic performance of the former. This means the search continues. In this document, a combination of carefully chosen refrigerant components are carefully blended to come up with a simulation based R22 long term replacement, which will be referred to in this document as BTEP.
- Full Text:
- Date Issued: 2017
- Authors: Bantan, Mafor Glory
- Date: 2017
- Subjects: Air conditioning
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4857 , vital:28537
- Description: The difficulty that exists in accurately monitoring the performance of air conditioners has made performance prediction an arduous task. Nevertheless, the performance still needs to be monitored and predicted as it helps solve a lot of problems resulting from this technology like effect of the technology on the grid, energy consumption, water utilisation and GHGs emission. With the introduction of regression modelling as a means of system monitoring and prediction some years ago, the accuracy was still a call for concern. It is worth realising that increasing the number of predictors will enhance this method’s accuracy. As such, this document intends to increase the accuracy of this method’s monitoring and predicting ability by increasing the number of predictors to cut across system thermal, environmental and human behavioural variation. These predictors experimentally gotten are used to build an environ-behavioural model that monitors the coefficient of performance and energy consumption of a domestic split-type air conditioner with higher accuracy. Refrigerants have undergone evolution in the past decades in a bid to come up with a refrigerant that has zero ODP, lower – than – R22 GWP and much better than R22 thermodynamic performance. No pure refrigerant has been found to possess these qualities as such mixtures or blends are the best shot at the moment. R410A could stand the test of time to be the long term R22 replacement but for the fact that besides R410A’s higher GWP than that of R22, the former’s system performance is lower than that of the latter’s due to the lower thermodynamic performance of the former. This means the search continues. In this document, a combination of carefully chosen refrigerant components are carefully blended to come up with a simulation based R22 long term replacement, which will be referred to in this document as BTEP.
- Full Text:
- Date Issued: 2017
Yield responses, mineral levels of forages and soil in old arable land planted to four legume pasture species in Lushington communal area, South Africa
- Authors: Gulwa, Unathi
- Date: 2017
- Subjects: Forage plants -- South Africa -- Eastern Cape Minerals in animal nutrition Communal rangelands -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2799 , vital:28091
- Description: This study was conducted in the old arable land located in Lushington communal area in the Eastern Cape province of South Africa. The objectives of the study were to assess the effect of legume introduction on biomass yield, forage and soil mineral levels of the arable lands planted to four leguminous pastures in four seasons. Planting was done in March and October 2008 in Lushington. All legumes were subjected to grow under rain fed conditions. Trifolium vesiculosum (arrowleaf clover), Lespedeza cuneata (sericea lespedeza), Trifolium repens (white clover) and Lotus corniculatus (birdsfoot trefoil) are the four forage legume species that were sampled for the purposes of this study. The four legume species persisted out of the fourteen species that were initially tested for adaptability and persistence in the environmental conditions of Lushington communal area. The legumes, grasses and soils from these legume plots were sampled to determine the effect of legume introduction on the forage yield, mineral contents of the companion grasses and soils over four seasons. Plant and soil samples were collected once in spring (November) 2013, summer (February), autumn (March) and winter (May) 2014 for biomass production, macro and micronutrients determination. Results indicated that legume inclusion and season affected (P < 0.05) the total dry matter (TDM) yield production. Plots with Lespedeza cuneata had the highest TDM (1843 kg/ha) and control plots had the least dry matter production (1091 kg/ha). Summer season provided the highest (P < 0.05) TDM compared to the other seasons. Both legume and grass quality was also affected (P < 0.05) by legume inclusion in different seasons. Accordingly, grasses harvested from Trifolium repens plot showed higher CP level (10.90 percent) than those harvested from other plots whereas the lowest grass CP content (6.90 percent) was measured in the control treatment. L. cuneate had the highest (P < 0.05) CP level (11.00 percent) and T. repens had the least CP (6.63 percent) level. Grasses harvested in autumn had the highest (P < 0.05) CP level (12.50 percent) and those harvested in winter had the least CP level (4.60 percent). Similarly, all legume pastures harvested in spring had superior (P < 0.05) CP (10.80 percent) levels and those harvested in winter had the least CP (3.50 percent) level. Legume inclusion had an effect (P < 0.05) on both grass and legume macro nutrient contents. Trifolium repens plot had the highest grass K (1.07 percent), Ca (1.50 percent) and Mg (1.83 percent), whereas there were lower K (0.12 percent), Ca (1.25 percent) and Mg (1.08 percent) contents in grasses harvested from the control and T. vesiculosum plots, respectively. In legumes, macro nutrient concentrations: K (0.68 percent), Ca (1.75 percent) were superior in the T. vesiculosum plot in comparison to other plots. Season also affected (P < 0.05) both grass and legume macro nutrient content. There was higher K (0.90 percent), Ca (1.30 percent) and Mg (0.94 percent) content in grasses harvested in autumn whereas there were lower levels in winter harvests. In legumes, superior K (0.74 percent) and Mg (1.87 percent) content were attained during spring while the least were measured in winter (0.07 percent) and autumn (0.75 percent), respectively. Likewise, both legume inclusion and season had an significant effect (P < 0.05) on the forages micronutrient levels. During spring, there was superior soil P content (36.28 mg/kg) while during autumn; there was less P (22.58 mg/kg) content. The highest SOC level (1.49 percent) was measured in the T. repens plot whereas the lowest SOC (1.15 percent) was attained in the control plot. The results of this study showed that grass legume mixtures produced forages with high nutrient content and herbage yield. Legume planting in the old arable lands has a potential to improve soil quality parameters such as soil P and SOC content.
- Full Text:
- Date Issued: 2017
- Authors: Gulwa, Unathi
- Date: 2017
- Subjects: Forage plants -- South Africa -- Eastern Cape Minerals in animal nutrition Communal rangelands -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2799 , vital:28091
- Description: This study was conducted in the old arable land located in Lushington communal area in the Eastern Cape province of South Africa. The objectives of the study were to assess the effect of legume introduction on biomass yield, forage and soil mineral levels of the arable lands planted to four leguminous pastures in four seasons. Planting was done in March and October 2008 in Lushington. All legumes were subjected to grow under rain fed conditions. Trifolium vesiculosum (arrowleaf clover), Lespedeza cuneata (sericea lespedeza), Trifolium repens (white clover) and Lotus corniculatus (birdsfoot trefoil) are the four forage legume species that were sampled for the purposes of this study. The four legume species persisted out of the fourteen species that were initially tested for adaptability and persistence in the environmental conditions of Lushington communal area. The legumes, grasses and soils from these legume plots were sampled to determine the effect of legume introduction on the forage yield, mineral contents of the companion grasses and soils over four seasons. Plant and soil samples were collected once in spring (November) 2013, summer (February), autumn (March) and winter (May) 2014 for biomass production, macro and micronutrients determination. Results indicated that legume inclusion and season affected (P < 0.05) the total dry matter (TDM) yield production. Plots with Lespedeza cuneata had the highest TDM (1843 kg/ha) and control plots had the least dry matter production (1091 kg/ha). Summer season provided the highest (P < 0.05) TDM compared to the other seasons. Both legume and grass quality was also affected (P < 0.05) by legume inclusion in different seasons. Accordingly, grasses harvested from Trifolium repens plot showed higher CP level (10.90 percent) than those harvested from other plots whereas the lowest grass CP content (6.90 percent) was measured in the control treatment. L. cuneate had the highest (P < 0.05) CP level (11.00 percent) and T. repens had the least CP (6.63 percent) level. Grasses harvested in autumn had the highest (P < 0.05) CP level (12.50 percent) and those harvested in winter had the least CP level (4.60 percent). Similarly, all legume pastures harvested in spring had superior (P < 0.05) CP (10.80 percent) levels and those harvested in winter had the least CP (3.50 percent) level. Legume inclusion had an effect (P < 0.05) on both grass and legume macro nutrient contents. Trifolium repens plot had the highest grass K (1.07 percent), Ca (1.50 percent) and Mg (1.83 percent), whereas there were lower K (0.12 percent), Ca (1.25 percent) and Mg (1.08 percent) contents in grasses harvested from the control and T. vesiculosum plots, respectively. In legumes, macro nutrient concentrations: K (0.68 percent), Ca (1.75 percent) were superior in the T. vesiculosum plot in comparison to other plots. Season also affected (P < 0.05) both grass and legume macro nutrient content. There was higher K (0.90 percent), Ca (1.30 percent) and Mg (0.94 percent) content in grasses harvested in autumn whereas there were lower levels in winter harvests. In legumes, superior K (0.74 percent) and Mg (1.87 percent) content were attained during spring while the least were measured in winter (0.07 percent) and autumn (0.75 percent), respectively. Likewise, both legume inclusion and season had an significant effect (P < 0.05) on the forages micronutrient levels. During spring, there was superior soil P content (36.28 mg/kg) while during autumn; there was less P (22.58 mg/kg) content. The highest SOC level (1.49 percent) was measured in the T. repens plot whereas the lowest SOC (1.15 percent) was attained in the control plot. The results of this study showed that grass legume mixtures produced forages with high nutrient content and herbage yield. Legume planting in the old arable lands has a potential to improve soil quality parameters such as soil P and SOC content.
- Full Text:
- Date Issued: 2017