The value of cover crops in crop rotation systems

The primary goal of a crop rotation system is to reduce soilborne diseases, improve soil structure and fertility, and support the beneficial organisms that decompose organic matter into nutrients.

- By Andries Gouws

When strategically integrating forage crops into such a system, they, along with crop residues, provide valuable feed for livestock – especially during the difficult late-winter months. This approach also presents a promising return on investment in forage crop establishment.

In situations where monoculture farming has led to soilborne diseases and weeds developing resistance to chemical control, crop rotation offers a natural alternative. According to Jamie Gerber of Barenbrug South Africa, regenerative agricultural methods are gaining traction in South Africa because they deliver multiple benefits, including improved yields, sustainable land use, healthier soil ecosystems, and reduced reliance on chemical fertilisers and pesticides.

Cover crops, she explains, are plants specifically chosen to benefit the soil within a crop rotation system, or when planted between rows of cash crops, fruit trees, or in vineyards. To fully harness the advantages of cover crops, it is essential to select the right species and varieties. Given the wide range of commercially available options, expert guidance is invaluable. The ideal choice depends on factors such as soil type, climate, and intended use – all of which differ from farm to farm.

Microbes and soil health

Microbes in the root zone of plants are connected to their hosts through a complex network of beneficial fungi. This relationship enhances nutrient availability for uptake by the roots while simultaneously improving soil structure. A diverse mix of cover crops supports these microbes by providing a balanced 'diet' through the release of different root exudates – chemical compounds secreted by various plant species.

The greater the diversity of plants, the broader the range of microbial species in the soil and the more resilient the soil ecosystem becomes. Soil microbes function much like those in a cow's rumen: