With summer approaching, farmers across South Africa's summer-rainfall regions are preparing for the return of warmer, wetter conditions. Heavy rainfall can bring welcome moisture, but intense or prolonged rain can also cause flooding, waterlogging, soil erosion, livestock health problems and damage to farm infrastructure. Preparing in advance can reduce these risks and help farms recover more quickly when extreme weather strikes.
So, what can a farmer do before heavy rainfall to reduce the damage?
1. Protect the Soil
Soils store key nutrients, organic matter and water (1). In wet weather, exposed soils risk being washed away, their nutrients becoming depleted and surface run-off entering waterways.
Cover crops can help protect bare soil from heavy rainfall and reduce erosion. Depending on the species selected, they can also contribute nitrogen, improve soil structure, increase water infiltration and add organic matter (2).
Common cover crops used in South African systems include cowpea, soybean, sun hemp, sorghum, pearl millet and sunflower (3), although the best choice depends on soil type, rainfall, cropping system and the farmer's objectives.
When heavy rain falls faster than soil can absorb it, water runs across the surface rather than moving into the soil. Improving infiltration can therefore reduce run-off and erosion while allowing more rainfall to be stored in the soil.
Mixed-species cover crops can provide long-term benefits to soil health and productivity (4), but monocultures can also help protect soil (5; 6). Varying root depths and associated biological activity can improve soil structure, water infiltration and organic matter, helping to build a more resilient farm (7).
Compacted soils are particularly prone to flooding and run-off. Heavy machinery and high stocking densities squeeze air pockets out of the soil, affecting its physical structure and its capacity to store and transfer water (8). But practical steps can be taken to avoid soil compaction as much as possible.
Driving on tramlines and using lighter machinery such as quads to check livestock during wet periods can reduce soil damage. Introducing rotational grazing can give fields time to rest between grazing cycles and reduce trampling. Lowering stocking densities during flooding can help fields recover more quickly, while using a sacrifice field can limit overall damage.
But surface run-off happens even on the healthiest soils. To slow its flow and reduce nutrients escaping farmland, hedgerows, trees and buffer strips can capture some of the water. In a study comparing the effectiveness of buffer strips, run-off was reduced by 33%, nitrogen losses by 44% and phosphorus by 50% compared with using no buffer strips (9). This is particularly important if farmland drains into surrounding waterways.
2. Protect Crops
Waterlogging deprives plant roots of oxygen, affecting crop growth and nutrient uptake (10). Improving drainage on the land can be an effective way of coping with waterlogged soils and planning for wet months ahead. There are multiple ways to do this, including digging drainage channels, building raised beds, adjusting sowing times and planting vigorous varieties (11).
3. Protect Livestock
In wet conditions, trampled grass and churned-up mud are particularly noticeable around ring feeders and water troughs. Moving livestock regularly, such as through rotational grazing, and reducing stocking rates can minimise soil damage. Rolling out hay bales in fields allows all animals access to feed while also increasing soil carbon through trampling loose hay into the ground (12).
These measures can also help optimise livestock nutrition. Prolonged wet conditions can affect pasture quality and nutritional value (13). Regularly moving livestock onto fresh pasture or providing supplementary feed can help address any nutritional deficit. Furthermore, overgrazed pasture recovers more slowly when exceptionally wet, making it important to avoid putting additional pressure on already damaged fields.
During wet conditions, livestock are at greater risk from certain diseases. Flooded waterways can contain contaminated water, while wet conditions can harbour pests and parasites such as liver fluke and lungworm and increase cases of foot rot. If kept outside, check livestock regularly for lameness and make sure they have access to shelter, such as trees or hedgerows.
If housed indoors, bedding should be clean and dry, and housing and feed-storage areas should be well ventilated. Warm, wet conditions can also increase the risk of calves developing pneumonia (14).
4. Protect Infrastructure
Maintaining infrastructure year-round can limit the damage caused during adverse weather. Leaky housing can affect livestock productivity, poor ventilation can contribute to disease, and insufficient storage can affect food or feed stores. Drainage systems and irrigation infrastructure should be continually monitored and
maintained to ensure they can cope with periods of heavy rainfall.
Farm roads, gateways and water crossings can also become difficult to use during periods of heavy rain. Improving roadways and gateways and keeping vehicles well maintained can save time, reduce costs and improve efficiency when conditions are challenging.
Before heavy rain arrives, checking drainage channels, culverts, dams, fences and other vulnerable infrastructure can help identify problems before they become more serious.
5. After the Rain
It is important to check livestock after flooding. Lameness may have been missed while farmers were busy with other jobs. Fields may be damaged and need resting before grazing animals are returned to them. Water quality should be checked for possible contamination and soil erosion assessed.
Avoid driving machinery onto saturated soils. Repair damage where necessary and, importantly, record what happened and what failed so that improvements can be made next time.
Extreme weather cannot always be prevented, but the damage it causes can often be reduced. Preparing soils, crops, livestock and infrastructure before heavy rain arrives gives farmers more options when conditions deteriorate. Building resilience is an ongoing process, with each event providing an opportunity to improve the farm's ability to cope with the next one.
Sources
- Chen, L., Rejesus, R.M., Aglasan, S., Hagen, S.C. and Salas, W., 2022. The impact of cover crops on soil erosion in the US Midwest. Journal of Environmental Management, 324, p.116168.
- Koudahe, K., Allen, S.C. and Djaman, K., 2022. Critical review of the impact of cover crops on soil properties. International Soil and Water Conservation Research, 10(3), pp.343–354.
- Grain SA, 2014. Conservation agriculture: Part 26. Accessed 3 September 2026.
- Sutton, E., Jain, M., Connell, K., Wang, H., Zhou, W., Deshpande, M. and Blesh, J., 2025. Increasing crop rotation diversity with cover crops builds climate resilience on farms. Environmental Research Letters, 20(12), p.124025.
- Blanco-Canqui, H., 2024. Do cover crop mixtures improve soil physical health more than monocultures? Plant and Soil, 495(1), pp.99–112.
- McKenzie-Gopsill, A., Mills, A., MacDonald, A.N. and Wyand, S., 2022. The importance of species selection in cover crop mixture design. Weed Science, 70(4), pp.436–447.
- Aglasan, S., Rejesus, R.M., Hagen, S. and Salas, W., 2024. Cover crops, crop insurance losses, and resilience to extreme weather events. American Journal of Agricultural Economics, 106(4), pp.1410–1434.
- Saco, P.M., McDonough, K.R., Rodriguez, J.F., Rivera-Zayas, J. and Sandi, S.G., 2021. The role of soils in the regulation of hazards and extreme events. Philosophical Transactions of the Royal Society B: Biological Sciences, 376(1834), p.20200178.
- Borin, M., Passoni, M., Thiene, M. and Tempesta, T., 2010. Multiple functions of buffer strips in farming areas. European Journal of Agronomy, 32(1), pp.103–111.
- Zhang, Y., Chen, X., Geng, S. and Zhang, X., 2025. A review of soil waterlogging impacts, mechanisms, and adaptive strategies. Frontiers in Plant Science, 16, p.1545912.
- Manik, S.N., Pengilley, G., Dean, G., Field, B., Shabala, S. and Zhou, M., 2019. Soil and crop management practices to minimize the impact of waterlogging on crop productivity. Frontiers in Plant Science, 10, p.140.
- FAI Farms, 2024. Outwintering. Accessed 2 September 2026.
- Farmers Guide, 2024. Warning over mineral levels after wet weather. Accessed 3 September 2026.
- Teagasc, 2023. 6 key steps to deal with wet conditions on beef farms. Accessed 3 September 2026.
