Improving food security in Africa via innovations in soil health and crop nutrition

Soil health is generally defined as the capacity to produce sufficient crop yields without compromising the future productive capacity of soils and the ecosystem services they regulate and deliver (International Fertiliser Development Centre). Large parts of the African continent suffer from poor soils and crop nutrition, threatening food security and making production more vulnerable to climate change.

In June 2023, we brought together UK and African experts to learn about the challenges and opportunities around building sustainable soil health and crop nutrition.

Click here to watch the event on replay.

The speakers gave an overview of innovations that could be used to boost soil health and crop nutrition in Africa, and how these could be incorporated into farming systems more effectively.

Two broad themes emerged as priorities to take forward:

• Biologically based solutions could be used to boost soil health and crop fertility.
• Both external investment and capacity building for farmers are essential.

Read on to find out more about soil health and crop nutrition from our speakers.

Current practices for soil health and crop nutrition

Increasing crop nutrition – and consequent food production – generally relies on fertilisers to deliver nutrients like Nitrogen, Phosphorus, and Potassium (NPK) to soil and plants. Synthethic NPK fertilisers are highly effective at boosting production. However, they are very expensive for African farmers, and if applied inefficiently, can undermine long-term soil health.

According to speaker Sylvia Nyawira from CIAT (International Centre for Tropical Agriculture), Soil organic carbon (SOC) is the key determinant for ecosystem services. Increasing SOC is therefore fundamental to improve overall soil health and food production. SOC can be boosted through NPK fertilisers. However, this strategy is less effective in Sub-Saharan Africa than in other parts of the world due to degraded soils (IFDC).

Management practices are vital for improving SOC (IFDC). Since 2003, CGIAR have trialled various agroecological practices like intercropping, minimum tillage, NPK variations and deep-rooted forages. Sylvia outlined the clear benefits of these practices for SOC and food production. Such practices should be advanced and supported by biophysical modelling to improve outcomes.

Whilst synthetic fertilisers remain an essential tool, there are many avenues for boosting soil health and crop nutrition that are being explored by organisations in the UK and Africa.

Innovations to improve soil health and crop nutrition

Biostimulants 

Biostimulants contain substances and/or microorganisms that stimulate the natural processes of plants. Laura Bishop from Plant Impact and John Haywood from Unium Biosciences  (two innovative UK companies working on biostimulants) explained how their innovations boost productivity. These biostimulants contain compounds, substances and micro-organisms that can be applied to plants, soils and seeds to increase root and shoot biomass whilst simultaneously reducing abiotic stress.

Biofertilisers 

Biofertilisers work in a similar way to biostimulants, but contain additional nutrients to mirror more closely the impact of synthetic fertilisers. Romney Jackson (Sylgen Animal Health) explained how they repurpose slurry into a biofertiliser that promotes plant growth and can be used as a foliar spray on crops. Tilahun Amede (AGRA) suggested transferring urban waste to rural areas and building inoculant centres to boost biofertiliser production.

Organic amendments 

Composting (applying recycled organic materials to soil) is another way to organically improve soil health, according to soil scientist Laura Atuah (Kwame Nkrumah University of Science and Technology). Overapplication of synthetic fertilisers can disrupt PH levels and the balance of nutrients in the soil. Organic amendments like compost help restore soil organic carbon and long-term soil health (IFDC). Farmers should be supported in actively repurposing their organic waste into their soil to boost productivity. Similarly, planting crops like nitrogen-fixing legumes can also organically improve soil properties.

Landscape restoration 

There are broader scale initiatives that can further boost soil health and crop nutrition. Tilahun Amede listed landscape restoration, biomass conservation, regreening and rural renewable energy as key bio-based solutions. A combination of public policy, international collaboration and technological innovation can drive these forward.

Water retention 

Large areas of Africa are arid or semi-arid, with water marginal areas suffering rainfall shortages and poor rainfall distribution. Many households in these areas are therefore reliant on food handouts, according to George Nyamadzawo from Bindura University in Zimbabwe. Retaining water in these poor soils is therefore fundamental to soil health, food production and economic development.

George led a major Sub-Surface Water Retention (SWRT) project. The project instals HDPE polymer membrane sheets beneath the ground that store water, reduce nutrient leeching and increase yield compared with surface nets. 380 farming households have signed up. This is an essential example of a low barrier to entry technology that focused on local capacity-building.

George identified key opportunities in this area. Resources are needed for research into different crops, funding is needed to source improved materials, pilots should be set up in different areas, local communities and farmers should be trained, and an integrated approach should be taken with local and national institutions to build capacity.

Investment and capacity-building

At the most basic level, farmers need financial support to access diversified sources of fertilisers. Tilahun Amede (Alliance for a Green Revolution in Africa, AGRA) explained that investment in production, distribution and reach of fertilisers must be prioritised, especially regarding ‘last mile’ delivery systems and agro dealerships to improve access.

These changes could take place through both investment and regulation. According to Tilahun, the Africa Fertiliser Financing Mechanism should be expanded, and policy shifted to create regional regulatory frameworks to create local capacity for fertiliser and soil health tech production.

Companies have a key role to play in terms of reaching farmers. Unium Biosciences, Plant Impact, and Sylgen all mentioned working closely with distributors in Africa to reach broad a range of farmers and crops. They also referred to the importance of supporting farmers to be involved in field trials to generate data and improve products and decision making.

Next steps

Biologically based solutions and investing in capacity building are two excellent opportunities for UK and African organisations to collaborate to build better soil health and crop nutrition.

If you have an innovative idea or are looking to partner with another organisation, reach out to gcrf.agrifood@iuk.ktn-uk.org and we can support you.