It is all about sustainability, says Izak Dreyer, a producer running a mixed farming enterprise at Ascent, near Vrede in the Free State. “It is quite clear that the use of cover crops in a rotational crop production system is ecologically as well as economically sustainable. Apart from the advantages to the soil, input costs are reduced significantly, while yields increase or, at the very least, stay the same.
“From a practical point of view, the cover crop principle places our fodder flow situation in a different league. We still have a lot to learn about the concept, but it is obvious that cover crops take the sting out of the difficult months of August to October.”
Factors determining the mix
According to Douw Steyn of seed company Barenbrug, there are various factors that determine the specific components of a multi-species cover crop mix. These include climate, growth period and finance. However, the purpose of the cover crop remains an essential factor. Some species in the cover crop mix may aid in weed and nematode suppression, alleviate compaction, provide organic matter and release chemicals, all while promoting good grazing potential.
“An important goal is to have various types of root systems that operate at different soil depths. We are looking for a combination of deep taproots, aggressive subterranean root systems, nitrogen fixers and as many root hairs as possible.”
Usually a multi-species cover crop mix consists of grasses, legumes, brassicas, and forbs (herb-like plants). Depending on whether the cover crop is winter or summer mix, the individual species may differ, but every species has a particular function and supports specific organisms in the soil. Such a diverse mix can therefore really jumpstart the microbes in the soil, he says.
Since cover crops have different functions, it is vital to determine what the crop is expected to do, according to Barenbrug’s Cover Crop Guide. Is the intention to add organic matter to the soil? Perhaps to add nitrogen to the cropping system or to stimulate soil biological activity? Or to protect the soil during the winter months?
You can read up to 3 premium stories before you subscribe to Magzter GOLD
Log in, if you are already a subscriber
Get unlimited access to thousands of curated premium stories, newspapers and 5,000+ magazines
READ THE ENTIRE ISSUE