Smallholder livestock farmers who depend on natural communal grazing lands are particularly vulnerable to climate change as well as to food insecurity and should be encouraged to grow drought-tolerant fodder crops. Moringa oleifera is a highly valued plant, due to its exceptionally high nutritional content. This study was conducted at two experimental sites in the Limpopo province of northern South Africa to evaluate for the first time the effect of plant density and cutting interval on biomass production and chemical composition of moringa grown under two diverse climatic conditions. Four different planting densities (435,000, 300,000, 200,000, and 100,000 plants/ha) were arranged in a randomized complete block design and experimental samples were replicated four times. Data for biomass and gravimetric soil moisture content were collected each time the plants reached a height of 50 cm. Harvested leaves were analysed for chemical composition. An increase in the plant density led to elevated biomass production at both study locations, ranging between 527 and 2867 kg/ha. Moringa is capable of meeting all nutrient requirements of livestock depending on harvest time and location.

Mulching is regarded as the most important of the three conservation agriculture principles in increasing crop yield in the short term. Thus, the main objective of this study was to investigate the impact of mulch type and mulch application rate on biological nitrogen fixation (BNF), physiological and yield responses of cowpea. A multi-locational (two locations) and multi-seasonal (two seasons) study was carried out under rainfed conditions in the Limpopo Province of South Africa. Three mulch types (Moringa oleifera stems; Moringa oleifera leaves and twigs; and Vachellia karroo leaves and stems) were uniformly spread on the surface at four rates (0, 3, 6, 9 t/ha). The application of mulches, regardless of the rate and type, improved cowpea chlorophyll content and agronomic parameters, such as stem diameter and plant height. Grain yield at Syferkuil responded to the mulching effect in both seasons, while at Ofcolaco, differences were only observed in one of the seasons. Cowpea under control discriminated against ¹⁵N more than under mulched treatments, resulting in more than 70% of the nitrogen being derived from air compared to 50% in mulched plots. This study demonstrated that organic surface mulches improved the physiological responses of cowpea and that organic surface mulches with a lower C:N ratio significantly reduced BNF.