No abstract

Burkea africana is a leguminous tree used for medicinal purposes, growing in clusters, on soils impoverished from most nutrients. The study aimed to determine the factors responsible for successful reproduction and establishment of the B. africana trees in nature, as all efforts for commercial production has been proven unsuccessful. An investigation was carried out to determine the metabolomic profile, chemical composition, and microbial composition of the soils where B. africana grows (Burkea soil) versus the soil where it does not grow (non-Burkea soil). 1H-NMR metabolomic analysis showed different metabolites in the respective soils. Trehalose and betaine, as well as a choline-like and carnitine-like compound, were found to be in higher concentration in Burkea soils, whereas, acetate, lactate, and formate were concentrated in non-Burkea soils. Liquid Chromatography-Mass Spectrometry analysis revealed the presence of numerous amino acids such as aspartic acid and glutamine to be higher in Burkea soils. Since it was previously suggested that the soil microbial diversity is the major driver for establishment and survival of seedlings in nature, Deoxyribonucleic acid (DNA) was extracted and a BLAST analysis conducted for species identification. Penicillium species was found to be highly prevalent and discriminant between the two soils, associated with the Burkea soils. No differences in the bacterial composition of Burkea and non-Burkea soils were observed. The variances in fungal composition suggests that species supremacy play a role in development of B. africana trees and is responsible for creating a supporting environment for natural establishment and survival of seedlings.

Previously, researchers have not paid attention to indigenous African leafy vegetables such as nightshade and kale, however, amaranth species have recently gained popularity due to their adaptability to various climatic conditions and their cultivation in both open fields and hydroponics. Amaranth species are ranked among the underutilized leafy vegetables with medicinal properties, economic values, nutritional and health benefits. This study aimed to compare the growth parameters and nutritional composition of two consumed red (Amaranthus Cruentus L.) and green (Amaranthus Graecizans L.) amaranth species in South Africa, cultivated in an open field versus a greenhouse. The findings showed a high chlorophyll content and large leaf area under open field conditions on red and green species. The number of leaves and stem height were higher in the greenhouse cultivation system. In open field cultivation, minerals such as calcium, magnesium, phosphorus, iron, zinc, aluminium, copper and manganese for both species were significantly higher whilst potassium, sodium, boron, sulphur were significantly higher in the greenhouse production. The sufficient total nitrogen and ash were recorded in the open field production, and no significant difference was observed between the open field and greenhouse on moisture and ash content of A. Cruentus. In conclusion, A. Cruentus and A. Graecizansn grown in an open field had higher proximate and mineral composition over the greenhouse cultivation system.

Low soil fertility in savanna soils has been linked to low crop yields, with nitrogen being the most limiting factor in crop yield. Soil used in this pot experiment was obtained from Motshephiri village with low total N, low NO3− and high NH4+. A pot experiment was conducted in a greenhouse laid in a Randomized Complete Block Design with four treatments (1) control, (2) Bradyrhizobium japonicum inoculant, (3) superphosphate and (4) Bradyrhizobium japonicum inoculant + superphosphate). The superphosphate was applied at three different levels (45, 60 and 75 kg/ha). Lablab was cultivated in each treatment and the results of the study indicated that lablab growth significantly increased total N and NO3−, and reduced concentration NH4+ relative to the original soil herein referred to as pre-lablab growth. However, the N forms (total N, NO3− and NH4+) did not differ significantly amongst different levels of superphosphate with or without Bradyrhizobium japonicum inoculant. Lablab growth, proved to have a significant impact on both the soil macro (P, K, Ca, Mg, and Na) and micronutrient level (Fe, Mn, Cu, B and Cl) with the exception of Zn. This study suggests that lablab’s ability to rapidly boost soil N content, overall soil fertility in a short period of time without the use of superphosphate fertilizers or Bradyrhizobium japonicum inoculants makes it ideal for intercropping or rotating with non-leguminous crops that have a short growing season.

Gonimbrasia belina (mopane worm) and Cirina forda caterpillars (Lepidoptera: Saturniidae) are mostly found in shrubs and trees, from where they are collected as larvae and are widely consumed across southern Africa by rural and increasingly urban populations. These caterpillars are among the most prominent, traded, and economically beneficial edible insects found in Western African countries, but also in South Africa, Zimbabwe, Botswana, and the Democratic Republic of the Congo. Over the years, these caterpillars have evolved from being part of the diet in various communities to playing a vital role in income generation. In addition, consumption of G. belina and C. forda caterpillars as potential food sources has gained momentum due to their potential for contributing to livelihoods and mitigating food security challenges across Africa while providing significant benefits to developing countries on a socio-economic and ecological level. Edible caterpillars serve as a good source of rich nutrients such as proteins, fatty acids, and micronutrients and can be used in formulating nutrient-dense complementary foods. However, limited information is available, specifically on different trees that serve as hosts to these caterpillars, as they depend on the leaves as their only source of food. In addition, the review aims to critique and document knowledge on the nutritional benefits, acceptance of the use of these caterpillars as food security, commercial value, and level of acceptance towards the utilization of caterpillars as food sources.