Rejuvenating soil health to reverse climate change, boost crop yields

Climate Active National Organic Permaculture Syllabus Academy members planting grass in Nyali, Mombasa County.


What you need to know:

  • For centuries, the world has relied on soil for 95 percent of its food needs through agriculture.
  • Healthy soil, consisting of mineral material, microorganisms, air and water nourishes plants and promotes faster growth and higher productivity.

The world needs to produce more food to cater for its growing population. However, various factors including climate change have gradually caused a decline in food production. Among them, climate change is causing frequent and severe weather events like droughts, floods and heat waves, disrupting agriculture, damaging crops and affecting the food distribution system.

For centuries, the world has relied on soil for 95 per cent of its food needs through agriculture. Healthy soil, consisting of mineral material, microorganisms, air and water nourishes plants and promotes faster growth and higher productivity. Conversely, unhealthy soil lacks the necessary nutrients for plants, resulting in stunted or no growth.

Conventional agricultural practices heavily contribute to and suffer from climate change in a destructive cycle. Years of soil degradation have diminished its ability to produce healthy food. One major issue is reduced rainfall, which deprives the soil of water, 25 per cent of its composition, and hampers its nutrient supply to plants. Extended dry seasons lead to groundwater depletion, high evaporation rates and increased soil salination.

In 2015, the Food and Agriculture Organization of the United Nations (FAO) reported that 33 per cent of soils suffer moderate to high degradation due to unsustainable practices. Erosion, soil carbon loss, nutrient imbalances, acidification, contamination, water logging, compaction, salination and biodiversity loss from agriculture have rendered the soil incapable of natural processes.

According to FAO, adopting Sustainable Soil and Land Management practices is the solution. These proven techniques maintain or improve soil health and productivity while minimising adverse environmental effects, aligning with SDG 15.3's objectives of addressing desertification, restoring degraded land and combating land degradation.

Soil amendment emerges as a fast and effective way to reverse climate change and boost crop yields. Many farmers have embraced organic farming methods, which restore soil balance and reduce reliance on synthetic inputs. This is a positive step as research shows that organic agriculture can yield 40 per cent more during droughts. However, organic practices mainly focus on the surface layer of soil through composting.

 Paul Ketterer, the founder of  Climate Active National Organic Permaculture Syllabus Academy, a non-profit organisation,  and his team advocate for the broader adoption of soil regeneration practices among farmers. Working closely with the Wildlife Clubs of Kenya (WCK), they have conducted experiments on challenging soils along the Kenyan Coast, including salty and coral soil.

Surprisingly, the team successfully grew healthy grass on these soils without using common synthetic fertilisers, pesticides or herbicides. Their secret, they say, lies in microbial practices, which involve replenishing depleted soil components.

By reintroducing the right quantities of these components, the team aims to restore the soil's structure and enhance productivity gradually. These remarkable findings have sparked significant interest among farmers who seek to improve productivity while mitigating the effects of climate change.

In a recent development, the Mwea Irrigation Scheme team visited Paul’s testing site to learn about soil recovery techniques, as they aim to revive their depleted rice paddies and protect farmers from further losses.

The chairman of Archbishop Gitari Primary School, Reverend Dr John Baptista Mwangi, who led Mt Kenya Delegation of Teachers and Farmers in this endeavour, reported success. Emphasising the need for more farmers to adopt the sustainable method, he explained that most grasses and plants they found excelling there only do well in healthy soil. He concluded, ‘growing grass on these soils is like giving life to dry bones.’

Paul is not working alone. The team is testing a microbiome methodology product that rejuvenates delicate soil diversity by balancing the necessary chemical, physical and biological processes.

Comprising more bacteria than fungi, the product is added to the soil at the onset of the planting season. Paul explains this is necessary since the topsoil is 90 per cent fungi and 10 per cent bacteria.

Paul highlights the detrimental effects of constant chemical use in agriculture including destroying beneficial microbiomes, imbalanced soil biodiversity and increased invasiveness of plants and pathogens. This reduces crop productivity and contributes to carbon emissions and global warming. The microbiome methodology promotes soil organic matter and bacterial content, aiding in carbon retention and slowing GHG emissions. It effectively balances soil components and mitigates pest attacks. Applying deep soil treatment promotes the generation of humus, which provides abundant nutrients to plants.

In contrast to compost, which encourages weed growth, humus supports rich soil components where minerals, organic matter, water and air are balanced. The optimal functioning of roots, facilitated by microbial activities, enhances water infiltration and promotes better air circulation. This, in turn, improves mineral proportions and boosts productivity, resulting in healthy, weed- and pest-resistant crops.

In addition to its benefits for soil health and food productivity, microbiome agriculture also significantly addresses climate change by retaining more carbon in the soil, helping slow emissions and combat global warming. Regenerative agriculture is crucial for sustainable food production, especially in the climate crisis. Intensive practices have harmed soil structure and increased carbon emissions. Adopting SSLM methodologies like microbiome technology offers hope for feeding the nation and supporting SDG 15.

Accessible information can help farmers implement SSLM practices, restoring soil balance, reducing reliance on costly synthetic inputs and promoting carbon sequestration. Ongoing research and testing in diverse farming areas will provide valuable insights into the effectiveness of microbiome technology. By embracing sustainable practices, agriculture can become a resilient and food-secure sector and aid in removing atmospheric carbo