A guide to sustainable dry bean farming

Dry beans are a vital crop in South Africa, not only as a nutritious and affordable source of protein for households but also as a cash crop with significant economic potential.

Dry beans play an important role in diversifying cropping systems, improving soil fertility through nitrogen fixation, and contributing to food security across the country. Both small-scale and commercial farmers stand to benefit from cultivating dry beans, particularly as demand continues to grow in local and regional markets.

Lucia Ndlala, a plant-breeding PhD candidate and dry bean researcher at the Agricultural Research Council (ARC), emphasises that while opportunities for production are promising, farmers must also navigate various challenges. She shares valuable insights on best cultivation practices, market trends, and strategies to overcome production barriers for sustainable growth in South Africa’s dry bean industry.

Dry beans are legumes that are purposefully dried after harvest. According to Ndlala, the goal is to get their moisture content under 15%, a process that’s key to extending shelf life and preventing spoilage.

While this drying makes them easy to store at room temperature, they must be soaked and cooked to eliminate the harmful compounds they contain before they are safe for consumption.

Common dry bean varieties

Understanding the different types of dry beans is crucial for targeting the right market. Ndala explains the most common varieties cultivated in South Africa:

Small white canning beans: “The most commonly cultivated ones. These ones are mainly focused on the canning industry,” she says.
Red speckled sugar beans: “You find them anytime in every single market that you go to, even your local ones. We normally use them for cooking and doing different local dishes.”
Red kidney beans: “These are mostly used for salads. Some are used for canning, but mostly they are prepared for their nutritional value.”
Black beans: “We don’t have a big market for it as of yet.” They are widely used in many countries.
Green beans: “Farmers should know that there is a market for green beans out there, though it is still growing.”

According to Ndlala, the planting season and crop cycle for dry beans in South Africa vary by region and cultivar. In provinces such as North West, Limpopo, and Mpumalanga, farmers typically plant between mid-October and December, aligning planting with the first rains and ensuring soil temperatures are above 15°C.

“If you have the cultivar recommendation booklet, it will tell you the different maturity dates of each cultivar that you’ll be planting, so you can plan accordingly for optimal yields,” Ndlala shares.

Dry beans (legumes) fix nitrogen in the soil, reducing the need for fertiliser. Photo: Wikimedia Commons

Production, markets, and export potential

South Africa’s dry bean market is stabilising. The majority of production (90%) is concentrated in three provinces: Limpopo, North West, and Mpumalanga.

According to the department of agriculture (DoA), Limpopo led provincial dry bean production with 47,1% of production (23 790 tonnes), followed by Free State (21.4%), North West (11.9%) and Mpumalanga (9.3%), while the rest of the provinces produced 10.3% in the 2023/24 season.

The country produces about 70 400 tonnes annually but consumes roughly 114 000 tonnes, according to another report by the DoA. This means South Africa only meets 61% of its domestic demand and must import to make up the deficit.

Ndlala notes that this creates a significant opportunity for local farmers, especially with the growing demand for health-conscious food choices.

For farmers considering export, it’s critical that their produce is disease-free and that they use quality seed to meet market standards.

South Africa consumes more beans than it produces, relying on imports to meet demand. Photo: Patricia Tembo/Food For Mzansi

Improving soil health

Dry beans are valuable for their ability to fix nitrogen in the soil. To ensure this process is effective, farmers should conduct a soil analysis before planting.

Ndlala advises working with an extension officer for this. Dry beans thrive in a neutral soil pH, which is essential for nitrogen fixation.

Planting beans as a cover crop is a great way to improve soil health and reduce costs.

“It is very important for farmers to consider what they are planning to do the next season. Including beans as their cover crop, since they fix most of the nitrogen, will save them a lot of money on buying fertiliser,” Ndlala advises.

Disease and pest management

Ndlala explains the following proactive management practices for preventing crop losses:

Scouting: Regularly check your fields for signs of pests or diseases.
Seed-borne diseases: Be aware of pathogens that can be present inside the seed, and pests, like red spider mites, that cause leaf damage.
Consult experts: Instead of immediately using chemicals, contact a pathologist or your local agricultural extension officer for an accurate diagnosis and recommended solutions.
Crop rotation: To prevent disease build-up, rotate your crops by planting something different, like maize or sorghum, in the following season.
Field hygiene: Properly dispose of infected plant debris to prevent the spread of diseases.
Resistant cultivars: Use certified, resistant seed varieties from reputable agro-dealers.

“The first thing we normally tell farmers when they notice something in their field is not to rush to use sprays. The most important step is to contact one of our pathologists. The pathologist will visit the field, identify the problem, and then inform the farmer of their findings. If a chemical solution is appropriate, the pathologist will advise the farmer to visit an agro-dealer to get the recommended product to address the pest issue,” Ndlala says.

Irrigation, harvest and storage

Dry beans are highly water-sensitive, especially during three critical stages: germination, flowering, and pod filling. “If you’re having inconsistent watering in your fields, it can lead to poor germination.”

Ndlala recommends centre pivots and sprinkler systems for consistent water coverage, as furrow irrigation can lead to waterlogging and root rot.

To check if your beans are ready for harvest, Ndlala explains that farmers should pick a pod and listen for a rattling sound when shaking it. According to a guide compiled by the DoA, dry beans reach physiological maturity when their moisture content is about 50%, but they are only ready for harvesting once the moisture level has dropped to 15–16%.

This drying process usually takes four to six weeks after physiological maturity, depending on the region and weather conditions. Harvesting too early can cause poor quality, while delaying harvest increases the risk of pods shattering in the field. The best time to harvest is when all pods have turned yellow, but before they become overly dry and start to crack open.

When it comes to post-harvest, proper storage is essential to prevent losses, particularly from bean weevils.

“It is important that after you’ve done your packaging, you take your packaging into a cooler, dry place or dark place where those bean weevils won’t develop quickly.”

Harvesting should take place at 15–16% moisture content to avoid seed damage. Photo: Patricia Tembo/Food For Mzansi

Common mistakes to avoid

Ndlala identified these recurring challenges for farmers:

Poor soil preparation and a lack of soil analysis.
Planting uncertified or untreated seed.
Ignoring resistant cultivars.
Inadequate knowledge of spacing, pest control, and timing.
Post-harvest losses from mould, pests, or poor storage.

She advises farmers to seek out workshops and on-farm training to gain the technical knowledge needed for success. “The most important thing is that beginner farmers gain the technical knowledge of how and when to plant to achieve proper yields.”