In well-maintained veld, the opportunity to significantly increase soil carbon is quite limited, as these ecosystems are already balanced, making substantial gains unlikely, says production scientist Dr Justin du Toit.

Conversely, he adds, degraded lands, which have reduced soil carbon levels, present a valuable opportunity for restoration. This is particularly true in areas with spekboom, a plant known for its carbon sequestration potential.

However, achieving noticeable results in these regions can take decades, and the effectiveness of restoration efforts can vary greatly.

In arid and semi-arid regions, soil carbon is prone to decomposition due to the cycles of wet and dry periods, making it difficult to establish a stable, long-term increase in soil carbon. Severe droughts can also undermine any progress made in these systems, explains Du Toit.

Furthermore, he says it is important to differentiate between the various types of soil carbon. Unprotected carbon, which includes microbes and plant residues, fluctuates seasonally and decomposes easily.

In contrast, physically protected carbon is associated with soil structure and can be enhanced through practices like no-till farming. Lastly, biochemically protected carbon is highly resistant to decomposition but accumulates very slowly, taking decades or even centuries to build up.

Thus, says Du Toit, when people claim that their ‘soil carbon’ has increased, that in itself is not very useful if they don’t state what type of carbon they are referring to.

Carbon credits

Then there are carbon credits and their economic implications, which are only loosely connected to the science of carbon.

In the past, incentives have had positive and negative consequences. For example, biofuels were once considered a ‘wonder solution’, but in some areas they led to huge carbon losses, particularly when areas like the Amazon rainforest were cleared for oilseed cultivation.

Currently, farmers are being offered financial incentives to modify their management strategies, often under the umbrella term ‘regenerative agriculture’. However, according to Du Toit, that term means almost nothing.

One possibility is that individuals have accessed funds aimed at encouraging improved farming practices, and farmers receive payment if they agree to implement specific new agricultural practices. Again, Du Toit says the scientific validity of these practices is questionable, unknown, or even entirely incorrect.

Nonetheless, it is acceptable for farmers to accept such funding, as long as it is essentially unconditional, other than perhaps implementing some changes in management. If it involves being repaid at a later date after certain conditions are met, Du Toit advises against entering into any agreement.

Guidelines

Du Toit gives farmers the following advice:

• Follow well-established good management practices, as they are inherently carbon friendly. Enhanced soil carbon is linked to various benefits, applicable to extensive livestock farming and crop farming.
• Understand that soil carbon in extensive systems is largely out of your control.
• Be wary of any management intervention that claims to deliver huge profits or significant ecosystem improvements, as they are often misleading.
• It is okay to accept financial compensation, as long as it does not require repayment and does not involve major changes in day-to-day farming activities.

Can you really farm carbon?

In his research on carbon farming, Roelof Bezuidenhout found that one researcher calls it the ‘carbon credit bandwagon’, arguing that carbon sequestration in semi-desert areas and much of our grasslands is largely ineffective. According to the researcher, at best, these regions might see a 3% improvement.

Another researcher said that 3% is hopelessly out of reach and that many schemes being sold to farmers are totally optimistic and not based on sound science.

Apparently, says Bezuidenhout, measurements taken on high-density grazing farms in the Eastern Free State and wetter parts of the central Free State have shown some improvement in carbon levels, root growth and soil properties, but that’s about it.

In the Eastern Cape, a 100 000ha spekboom rehabilitation project is under way. Participants are offered long-term contracts, with the promise of earning carbon credits about five years after planting. Currently, the carbon price is about $8/t (around R140/t), but speculators hope it could rise to $200/t (R3 500/t).

It’s envisaged that replanted spekboom veld could sequestrate two or three tons per hectare in the first few years and up to eight tons per hectare when nearing maturity.

Approach to carbon credit schemes

As farmers consider carbon credit schemes to enhance their sustainability and create additional revenue, Du Toit says they should take the following into account:

• Scrutinise the science – Many carbon credit schemes are overly optimistic and may not be grounded in solid science, especially in South Africa’s regional contexts.
• Economics – The carbon market is volatile and predicting its future is challenging. Past initiatives, such as certain biofuel projects, have had unintended negative environmental consequences.
• Regenerative agriculture – The term is often used broadly and can be misleading. It is essential to understand the specific practices involved and the scientific evidence supporting them.
• Contracts and commitments – Long-term contracts, such as 30- to 40-year agreements with relatively new companies, must be carefully considered, as the longevity and reliability of these organisations are uncertain.

Above all, Du Toit says it is important for farmers to stick to proven agricultural practices, because adopting well-established management practices not only benefits the farm but also supports environmental health. These practices naturally support soil health and carbon retention.

Additionally, factors like climate and soil type limit one’s ability to control soil carbon levels in extensive systems. Therefore, it is important that you know the limitations of your land. Farmers should also be sceptical of schemes that promise significant profits or ecological benefits with minimal effort or drastic changes.

Finally, Du Toit reiterates that financial incentives should not involve repayment or onerous obligations, and any required changes to farming practices must be practical and beneficial beyond the immediate scope of the scheme.

Email Justin du Toit at [email protected].