South Africa Wine Technical Yearbook 2025

NOVEMBER

DESMOND THOMPSON

Rooted in research – what science says about regenerative viticulture Part 2: Cover cropping and weed management By Lucinda Heyns

This article is based on a recently published scientific review article. In the review article, the question was: ‘What science exists to support the efficacy of practices used in regenerative viticulture systems or approaches?’.

Introduction – a scientific look at regenerative practices This article draws from a recently published scientific review that examined the current evidence supporting practices used in regenerative viticulture (RV). The review explored a range of individual, yet interconnected, vineyard strategies and evaluated how effectively they contribute to the core goals of RV. In Part 1, we covered the use of organic soil amendments, biostimulants, and biological control agents. This month, we turn our attention to cover cropping and alternative weed management, and the research that underpins these practices. Practice: Cover crops – greening the gaps for healthier soils and vines One of the defining features of RV is a commitment to keeping vineyard soils alive and thriving. Instead of the traditional bare soil approach between vine rows – often achieved with herbicides or frequent tillage – RV systems favour the use of cover crops. These are intentionally planted or the maintenance of naturally occurring vegetation

in the space between vine rows. Although cover crops aren’t a new concept in agriculture, their use in viticulture is gaining momentum for their benefits to soil health, vine performance and vineyard biodiversity. Soil health gains Cover crops bring life to the soil in more ways than one. Physically, deep-rooted species like forage radish help break up compacted soils and enhance structure. Legumes such as vetch and faba beans contribute to natural nitrogen enrichment through biological nitrogen fixation, reducing the need for synthetic fertilisers. As these plants grow and die back, they add organic matter to the soil via decaying roots and root exudates. This increases soil organic matter (SOM), boosting microbial activity and improving soil aggregation and pore structure. The result? Better water infiltration and retention – critical during both drought and heavy rain. Additionally, by reducing nutrient leaching, cover crops help vineyards retain valuable nitrogen and phosphorus, especially in sloped or erosion-prone landscapes like those found in Mediterranean regions.

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TECHNICAL YEARBOOK 2025