Due to the expansion of farming, many agricultural systems now depend more on chemical pesticides and inorganic fertilisers to boost farm output. Leguminous cover crops are used to improve soil fertility and to increase nitrogen availability for crop production. This review focuses mainly on evaluating the role of leguminous cover crops on soil's physical, chemical and biological properties. Furthermore, it focuses on the role of cover crops in crop biomass, grass nutritive value and crop-livestock grazing systems. This review used the Web of Science, Scopus and Google Scholar databases (accessed between January 2003 and December 2022). To find publications in the scope of the study, the authors combined different groups of keywords. The reviewed literature revealed that leguminous cover crops significantly increase yield due to an increase of nitrogen through nitrogen fixation. In addition, leguminous cover crops boost the forage's nutritional value, lowering feed costs and increasing livestock productivity. As a result of these findings, farmers can reap the benefits of leguminous cover crops in various ways, including enhancement of soil health, biomass, yield and reducing overall production costs.

The best management practices for cover cropping in citrus orchards, particularly in terms of species selection and termination methods, remain unclear. This study assessed the short-term effects of different cover crop species (vetch, medics and oats) and termination methods (slashed vs. non-slashed) on soil pH and enzyme activities (β-glucosidase, acid phosphatase, and urease) in a citrus orchard with sandy soil. A randomized complete block design with a factorial treatment structure and six replications was used. Soil samples were collected before and one year after cover crop establishment. The results showed that cover cropping increased soil pH from 5.42 to 6.00 after one year. However, no statistically significant differences were observed in soil pH or enzyme activities among cover crop species or termination methods. Marginal increases in enzyme activities were observed under leguminous cover crops, and these changes were insufficient to indicate strong treatment effects. Correlation and principal component analyses revealed that soil enzyme activities were more strongly influenced by soil properties (depth, carbon content and moisture) than by cover crop species or termination methods. These findings suggest that, under sandy soil conditions and within a one-year period, cover cropping has limited immediate effects on soil biological indicators in citrus orchards. Longer-term studies are recommended to assess cumulative impacts.

Cover crops are increasingly used in citrus production systems to improve soil health, reduce weed pressure and enhance fruit yield and quality. While the benefits of integrating cover crops into orchard management have been widely reported in several countries, information on their use under South African citrus-growing conditions remains limited. Therefore, this study was undertaken to investigate the influence of different cover crop species on soil organic carbon, weed biomass and citrus fruit yield under two cover crop termination practices, namely slashing and non-slashing. The cover crop treatments consisted of vetch, medics, oats and an untreated control without cover crops. The experiment was established as a split-plot arrangement within a randomized complete block design with six replications. Cover crop species constituted the main plot factor, while termination method was assigned to sub-plots. Soil was sampled before planting cover crops and one year after planting cover crops. Cover crop and weed dry weight samples were collected during the termination stage and fruit weight measurements were taken at harvest. Legume cover crops significantly increased Soil Organic Carbon (SOC) in the 0–30 cm soil depth, with vetch recording the highest SOC (0.6–0.8%), representing an increase of approximately 0.14% compared with oats. No significant SOC differences were observed at the 30–60 cm depth. Weed biomass declined markedly over time, from more than 1.4 t ha⁻¹ in 2021/22 to less than 0.6 t ha⁻¹ in 2022/23. Oats provided the greatest weed suppression, reducing weed dry weight to approximately 0.10 t ha⁻¹ in 2022/23, whereas the control treatment consistently recorded the highest weed biomass. Cover crop biomass was highest under oats in 2021/22 (1.50 t ha⁻¹), while excessive rainfall in 2022/23 reduced biomass production across treatments. Termination methods did not significantly influence weed biomass or cover crop biomass. Citrus fruit yield was not significantly affected by either cover crop species or termination method during the short-term study period. The findings indicate that legume cover crops improve SOC, while oats are more effective for weed suppression in lemon orchards. However, longer-term studies are needed to determine whether these soil and weed management benefits translate into increased citrus productivity.

Achieving sustainable agriculture requires environmentally friendly alternatives to synthetic insecticides. Hence, this review seeks to evaluate the sustainable use of syringa as a botanical pesticide in small-scale farming systems. The review applied an integrated literature review framework to synthesize published work on Melia azedarach L. use in insect pest control. Peer-reviewed and grey literature were sourced from multiple databases and repositories using defined keywords. No lower time limit was applied, and literature coverage included published work up to 2026. After screening 159 records, 99 studies were retained and thematically grouped into eight areas: botanical description, distribution, biopesticides and their mode of action, botanical insecticides and their benefits, Melia. azedarach L. as a botanical insecticide, the limitations on the usage of plant-based extracts and the effects of different extraction methods on the efficacy of Melia azedarach L. extracts. A narrative synthesis highlighted key findings, contradictions, and knowledge gaps while noting potential biases, including English-only sources. Studies indicate that Melia azedarach L. exhibits multiple modes of action, including repellency, antifeedant activity, oviposition deterrence, growth inhibition, ovicidal and larvicidal effects, and suppression of adult emergence. Despite challenges such as variability in extract composition, limited field standardization, and short residual activity, Melia azedarach L. shows considerable potential as a sustainable component of integrated pest management for small-scale farming. Future research should focus on standardized extraction protocols, field validation, formulation development, and commercialization to enhance adoption.