Evaluating the effects and benefits of cover crops in citrus orchards: a review

Abstract

Cover crops are used in sustainable agricultural practices to improve soil quality and minimise the effect of climate change, water restrictions and drought. The South African citrus industry produces and exports a diverse range of citrus fruits; however, knowledge of cover crops in citrus orchards in South Africa is limited. This review focuses mostly on evaluating cover crop selection, effects on the soil microbial community, weed control, citrus yield and fruit quality. In terms of cover crop selection, legumes seem to be preferred over non-legume cover crops. The reviewed literature reported that legume cover crops increased nitrogen by 67 to 209 kg N ha−1 through the nitrogen fixation process. Additionally, the cultivation of legume cover crops substantially improved the cost savings of nitrogen fertiliser. The fruit yield improved by 7.6 to 64%, while fruit quality improved by 2.3 to 12.4% fruit weight and 2.4 to 5.8% Bx. This demonstrates that the benefits of cover crops to South African citrus growers include improved soil quality and fruit yields and decreased costs.