Turning Back Desertification
In July this year I had the privilege of accompanying Peter Byck to Danie Slabbert's farm in Reitz in the Free State. Peter Byck's is the "wrangler" behind the Carbon Cowboys research, which has returned some incredible results from their multi dimensional study comparing regeneratively grazed farms with their conventional neighbours. Since our visit the results of Frits Van Oudtshoorn's 5 year study of Danie's veld by have been written up and the results are equally remarkable. Although the studies are very different they are linked by one metric, that of water infiltration. This metric ties in well with our last blog covering the desertification of the South African Highveld when the migrating herds were removed and replaced by continuous grazing.
The Carbon Cowboys science showed significant improvement in ecosystem function for all metrics under regenerative grazing - summarised below. In terms of water infiltration they recorded that soils under regenerative grazing infiltrated 3.5 inches per hour while the conventional only 1.5 inches per hour. That is 57% better for the regenerative soil! On Danie's farm the methodology was different but the results very similar. It took 5.5 minutes for an inch of water to infiltrate while on the neighbouring farm it took a little over 13 minutes, so more than twice as long for the conventional which means lots of runoff and less effective rainfall.
Peter Byck and Danie Slabbert, Reitz, July 2024.
Desertification is one of the greatest threats to keeping the planet habitable and is largely misunderstood as being a phenomenon associated with deserts and semi arid regions. Desertification can happen anywhere where our impact on the soil-plant ecosystem decreases the ability of the soil to infiltrate and hold water. Such soils have become desertified. Even if an area gets more than 1000mm of rain per annum, as is the case in the Carbon Cowboysresearch in the South Eastern United States, its soils can be desertified.
Simply put Desertification is when declining soil organic matter disrupts the Soil Carbon Sponge, causing soils to lose their functional capacity and the soil-plant ecosystem to spiral downwards. If a farm is only taking in and holding 40% of the rain that the farm over the fence is taking in, then its soil-plant ecosystem is going to be held back. Photosynthesis, which drives all our ecosystem services, can only happen when water is available. Imagine the impact of returning the Soil Carbon Sponge to our veld and doubling the water infiltration on all grasslands across South Africa. Imagine the impact that would have on food production, farm economics and water security.
Danie's family & friends learning about veld assessments on a good example of a 'grazing lawn'. Grazing lawns are common under selective grazing management.
The Results
Frits's study - THE IMPACT OF NON-SELECTIVE-GRAZING ON RANGELAND ECOLOGY - recorded the following changes over 5 years at Danie's farm:
- 50% increase in palatable grass species
- 80% increase in indigenous legumes
- 64% increase in biomass
- 60% increase in botanical diversity
- 2 x water infiltration rate
The story of the Carbon Cowboys' research and their results is covered in the exceptional Roots So Deep documentary which can be rented here. In summary they are:
- 25% more soil microbial diversity
- 33% more insect diversity
- 190% more grassland birds
- 50% more grassland bird species
- 13% more soil carbon
- 9% more soil nitrogen
- A sink of 3.3 tonnes of CO2e per year
- 57% more water infiltration
Together these two studies - separated by more than 12 000km, on different continents, with different soils, with different plants, and different climates - tell a powerful story of what Regenerative Grazing can do for the soil-plant ecosystem and ecosystem services and turning back Desertification.