scholarly journals Altering Nitrogen Sources Affects Growth Carbon Costs in Vachellia nilotica Growing in Nutrient-Deficient Grassland Soils

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1762
Author(s):  
Nonkululeko Sithole ◽  
Zivanai Tsvuura ◽  
Kevin Kirkman ◽  
Anathi Magadlela
Keyword(s):  
Soil Nutrient ◽  
Biomass Accumulation ◽  
Nitrogen Sources ◽  
Terrestrial Ecosystems ◽  
Eastern Africa ◽  
Burkholderia Contaminans ◽  
Kwazulu Natal ◽  
Physiological Adaptations ◽  
Microbial Symbiosis ◽  
The University

Vachellianilotica (L.) Willd. Ex Del. is a multipurpose leguminous tree that is common in grassland and savanna ecosystems in southern and eastern Africa. These ecosystem soils are reported to be acidic and nutrient-limited, specifically with regards to nitrogen (N) and phosphorus (P). The presence of this plant in these terrestrial ecosystems improves soil fertility benefiting the surrounding vegetation due to its ability to fix atmospheric N. This study seeks to understand the N-fixing bacteria symbiosis and physiological adaptations of V. nilotica in these acidic and nutrient-deficient KwaZulu-Natal soils. The soils used for this study were collected from the Ukulinga Grassland Nutrient Experiment located at the Ukulinga research farm of the University of KwaZulu-Natal, Pietermaritzburg, South Africa. Due to long-term soil nutrient addition treatments, these soils offered a diverse nutrient variation for better understanding the effects of acidity and nutrient variation on microbial symbiosis, plant nutrition, and biomass accumulation of V. nilotica. V. nilotica was able to maintain growth by relying on both atmospheric and soil-derived N across all treatments decreasing carbon (C) growth costs. There was an increased reliance on atmospheric-derived N of un-nodulated high N-treated plants. The plants grown in high N + P soils were able to nodulate with various species from the Mesorhizobium genus, which resulted in increased biomass compared to other plants. The results of this study show that V. nilotica can alter N sources to reduce C growth costs. In addition, both nodulating and free-living soil N2 fixing bacteria such as Caulobacter rhizosphaerae, Sphingomonas sp. and Burkholderia contaminans identified in the experimental soils may play an important role under P-deficient conditions.

scholarly journals Altering Nitrogen Sources Affects Growth Carbon Costs in Vachellia nilotica Growing in Nutrient Deficient Grassland Soils

2021 ◽  
Author(s):  
Nonkululeko Sithole ◽  
Zivanai Tsvuura ◽  
Kevin Kirkman ◽  
Anathi Magadlela
Keyword(s):  
Soil Nutrient ◽  
Biomass Accumulation ◽  
Nitrogen Sources ◽  
Terrestrial Ecosystems ◽  
Eastern Africa ◽  
Kwazulu Natal ◽  
Physiological Adaptations ◽  
Microbial Symbiosis ◽  
The University

Vachellia nilotica (L.) Willd. Ex Del. is multipurpose leguminous tree which is common in grass-land and savanna ecosystems in southern and eastern Africa. These ecosystem soils are reported to be acidic and nutrient limited, specifically with regards to nitrogen (N) and phosphorus (P). The presence of this plant in these terrestrial ecosystems improves soil fertility benefiting the sur-rounding vegetation due to its ability fix atmospheric N. This study seeks to understand the mi-crobial symbiosis and physiological adaptations of V. nilotica in these acidic and nutrient defi-cient KZN soils. The soils used for this study were collected from the Ukulinga Grassland Nutri-ent Experiment located at the Ukulinga research farm of the University of KwaZulu-Natal, Pie-termaritzburg, South Africa. Due to long-term soil nutrient addition treatments, these soils of-fered a diverse nutrient variation for better understanding the effects of acidity and nutrient var-iation on microbial symbiosis, plant nutrition and biomass accumulation of V. nilotica. V. nilotica was able to maintain growth by relying on both atmospheric and soil derived N across all treat-ments decreasing carbon (C) growth costs. There was an increased reliance on atmospheric de-rived N of un-nodulated high N treated plants. The plants grown in high N+P soils were able to nodulate with various species from the Mesorhizobium genus which resulted in an increased bio-mass compared to other plants. The results of this study show that V. nilotica can alter N sources to reduce C growth costs. Also, free-living N2 fixing bacteria play an important role under P deficient conditions.

scholarly journals Nitrogen Source Preference and Growth Carbon Costs of Leucaena leucocephala (Lam.) de Wit Saplings in South African Grassland Soils

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2242
Author(s):  
Nonkululeko Sithole ◽  
Zivanai Tsvuura ◽  
Kevin Kirkman ◽  
Anathi Magadlela
Keyword(s):  
South African ◽  
Leucaena Leucocephala ◽  
Biomass Accumulation ◽  
N Nutrition ◽  
Climatic Regions ◽  
Carbon Costs ◽  
Kwazulu Natal ◽  
Microbial Symbiosis ◽  
The Tropics

Leucaena leucocephala (Fabaceae) is native to Central America and has invaded many climatic regions of the tropics. In South Africa, the species is categorized as an emerging or incipient weed used as fodder, timber, firewood and in erosion control on degraded habitats. The species is common along the eastern subtropical regions of KwaZulu-Natal (KZN) Province, where it invades grasslands, savannas and edges of forests. Soils of these ecosystems are characterized as nutrient deficient and acidic. Using a pot trial, we determined the effects of the nutrient addition treatments on microbial symbiosis, N nutrition and biomass accumulation of L. leucocephala under greenhouse conditions. After 180 days of growth, plants were harvested, and their utilization of N derived from the atmosphere and from the soil was quantified through determination of δ15N values. L. leucocephala maintained growth and N nutrition by relying on both atmospheric- and soil-derived N across all soil treatments. The NDFA was significantly higher in high P (N1 + P, N2 + P and N3 + P) soils. L. leucocephala was able to nodulate with intermediate and fast-growing strains from the Mesorhizobium and Rhizobium genus in N2 + P grown plants. This shows that L. leucocephala possesses traits that are successful in acquiring nutrients, especially in nutrient limited conditions, by establishing plant symbiosis with multiple bacteria and relying on extracting N from the soil and from the atmosphere through the symbiosis.

scholarly journals How does the grade obtained at school for English and Mathematics affect the probability of graduation at a university?

Pythagoras ◽  
2017 ◽  
Vol 38 (1) ◽  
Author(s):  
Michael Murray
Keyword(s):  
Structural Equation ◽  
Equation Model ◽  
Mathematical Literacy ◽  
Percentage Point Increase ◽  
Point Increase ◽  
Kwazulu Natal ◽  
Specific Factors ◽  
And Mathematics ◽  
The University ◽  
Better Than

Over half of all students enrolling at a particular university in KwaZulu-Natal fail to complete a degree. This article is wanting to determine to what extent the marks they obtain for English and Mathematics at school impact on their probability of graduation at this university. In addressing this problem, other student specific factors associated with their gender, race and the type of school they have attended need also to be properly accounted for. To provide answers for this study, the performance of 24 392 students enrolling at the university over the period 2004 to 2012 was followed until they graduated or dropped out from their studies. A structural equation model was fitted because it allows one to separate a direct effect from that of an indirect effect. Gender, race and school background were found to be very significant with males, Black Africans and students coming from a less privileged school background having a smaller probability associated with eventually graduating from this university. Males tend to perform better than females in Mathematics, with females performing better males in English. More importantly, however, a single percentage point increase in one’s mark for English increases the probability associated with graduating from this university far more than would be the case if their Mathematics mark were to increase by a single percentage point. In the light of these mediated results, perhaps this university should be directing their efforts more towards improving the English (rather than mathematical) literacy of students entering the university.

scholarly journals Using an inductive approach for definition making: Monotonicity and boundedness of sequences

Pythagoras ◽  
2009 ◽  
Vol 0 (70) ◽  
Author(s):  
Deonarain Brijlall ◽  
Aneshkumar Maharaj
Keyword(s):  
Mathematical Thinking ◽  
School Curriculum ◽  
Further Education ◽  
Teaching Model ◽  
Advanced Mathematical Thinking ◽  
Structured Design ◽  
Kwazulu Natal ◽  
Teaching Of Mathematics ◽  
The University ◽  
And Training

The study investigated fourth–year students’ construction of the definitions of monotonicity and boundedness of sequences, at the Edgewood Campus of the University of KwaZulu –Natal in South Africa. Structured worksheets based on a guided problem solving teaching model were used to help students to construct the twodefinitions. A group of twenty three undergraduateteacher trainees participated in the project. These students specialised in the teaching of mathematics in the Further Education and Training (FET) (Grades 10 to 12) school curriculum. This paper, specifically, reports on the investigation of students’ definition constructions based on a learnig theory within the context of advanced mathematical thinking and makes a contribution to an understanding of how these students constructed the two definitions. It was found that despite the intervention of a structured design, these definitions were partially or inadequately conceptualised by some students.

scholarly journals Curriculum design in theology and development: Human agency and the prophetic role of the church

2016 ◽  
Vol 72 (4) ◽  
Author(s):  
Beverley Haddad
Keyword(s):  
Social Sciences ◽  
Curriculum Design ◽  
Social Issues ◽  
Development Programme ◽  
Theological Reflection ◽  
The Social ◽  
Kwazulu Natal ◽  
The University ◽  
The Church

The field of theology and development is a relatively new sub-discipline within theological studies in Africa. The first formal post-graduate programme was introduced at the University of KwaZulu-Natal, Pietermaritzburg, South Africa during the mid-1990s. In the early years it was known as the Leadership and Development programme and since 2000, as the Theology and Development programme. Over the past twenty years, this programme has graduated over 160 BTh Honours, 100 MTh, and 15 PhD students. This article outlines the history of the programme, addresses its ideological orientation, its pedagogical commitments and preferences in curriculum design. It further argues that theological reflection on “development” must seek to understand the prophetic role of the church in responding to the complexities of the social issues facing the African continent.  Key to this discussion is the contested nature of “development” and the need for theological perspectives to engage this contestation through a social analysis of the global structures of injustice. This requires an engagement with the social sciences. It is this engagement of the social sciences with theological reflection, the essay argues, that has enabled the students who have graduated from the Theology and Development Programme at the University of KwaZulu-Natal to assist the church and faith-based organisations to become effective agents of social transformation.

scholarly journals Mobile Technology as a Learning Tool in the Academic Environment

2019 ◽  
Vol 11 (2(J)) ◽  
pp. 92-102
Author(s):  
Sidwell Sabelo Nkosi ◽  
Rosemary Sibanda ◽  
Ankit Katrodia
Keyword(s):  
Mobile Technology ◽  
Low Income ◽  
Ordinary Least Squares ◽  
Cumulative Distribution ◽  
Educational Institutions ◽  
Learning Tool ◽  
Academic Activities ◽  
Kwazulu Natal ◽  
Educational Production ◽  
The University

Education in South Africa is not equally accessible, and the quality of education is not the same across all educational institutions. Students from low-income societies are scoring lower marks in contrast to students from higher income societies. The influence on this is the unavailability of efficient educational resources and infrastructure. This study uses a focus group of 300 students from the University of KwaZulu-Natal (UKZN) School of Economics. It attempts to examine and explain the effect of the use of mobile technology in academic activities within the school of economics at UKZN. The study divides the sample size into two groups, half is given mobile technology and the remaining group is deprived of mobile technology. The data is recorded in two educational production functions, namely Ordinary Least Squares and Logistic Regression Model. The cumulative distribution function examines the probability, in form of Logit, that a student passes economic if using mobile technology for academic activities or studying. Study findings indicate that it is imperative that institutions invest in mobile technology as their learning tool to improve throughput rate and it allows efficiency in all academic activities. Mobile technology enables students to be disciplined, effective and work ready.

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