How Does Soil Health Increase Resilience to Drought and Extreme Rainfall?

Extreme weather events, such as extended drought and heavy precipitation, are out of landowners’ and growers’ control; but through effective soil health management systems they can better manage how they prepare for and react to these circumstances.

Healthy soil allows more water to infiltrate and retains more moisture, enabling it to effectively absorb extreme rainfall as well as support crops during droughts. Adopting soil health systems before extreme events hit can save farmers significant time and money in the long run and preserve the vitality of their soils for many years to come.

Employing soil health systems by using practices such as no-till and cover crops, can help stabilize yields, improve agricultural productivity, and build resiliency through increased soil organic carbon content and soil water storage. These practices also benefit the environment, reducing nutrients lost through run-off, replenishing aquifers, and also acting as a natural filter for our waterways.

How exactly does soil retain water?

All soils have different amounts of sand, silt, and clay partilces and this affects water infiltration and soil water storage. While the proportion of these particles can’t be changed, farmers can increase the soil organic carbon in any soil and this optimizes their fields’ performance.

Soil organic carbon has two important functions for drought resilience: it can store up to 10 times its weight in water, and it is used as a source of food for soil microorganisms (bacteria, fungi, and other soil life) that build soil structure. This also creates habitat for the macrofauna, like earthworms, that make larger soil pores for water to drain so that it doesn’t pond on the surface and run-off, causing erosion and harming aquatic life. These two functions of soil organic carbon, water storage and drainage, work together to provide water to plants when they need it, while also allowing soils to drain so they don’t get waterlogged or erode.

What can farmers do to increase soil moisture levels?

Implementing soil health systems helps manage water, nutrients, and beneficial organisms in the soil year-round, helping  farms be prepared and resilient during unexpected events such as drought and extreme rainfall. The principles of soil health management (the foundation for regenerative agriculture)can be explored in further detail here.

Continuous living cover

When compared to healthy soils, bare soils are less absorbent and often compacted. The amount of run-off, nutrient loss, and soil erosion are significantly higher. In contrast, year-round cover provides more protection and shade, reducing evaporation loss. As a result, fields that have cover crops require less supplemental irrigation and can rely on stored soil water.

Studies have also shown that deep-rooted crops and perennials improved infiltration and the absorption of water in heavy rainstorms.

Lastly, roots of plants and plant residue on the soil surface aid in returning organic carbon to the soil and providing energy for soil microorganisms to carry out the vital functions that these creatures provide.

Implementing no-till systems

Tillage destroys soil structure, breaking down soil aggregates, and the effects can be felt for a number of growing seasons. When these break down, so do the pores between them, and the soil compacts and crusts further. As a result, the soil is less porous, leading to increased run-off and downstream flooding, further decreasing the amount of water stored in the soil for future times of need.

Considering a management change?

Adopting new management practices can bring challenges. Some farmers report it took them 2-3 years to learn how to use their new practices. Most start out small and then adopt more and more gradually over time. However, one thing is for sure – our environment is already changing. With the increasing severity and frequency of drought, heavy rain, elevated temperatures, market fluctuations, and many other factors outside of a farmer’s control, it makes sense to adjust management practices to help meet those challenges.

Managing to improve soil health brings many benefits, including drought resilience, increased nutrient availability, reduced input costs, and recent research also shows increased farm income. More and more resources are becoming available to help farmers transition to a soil health management system. Good places to start include your local cooperative extension office, NRCS, conservation district, and especially visiting with another local farmer who has already transitioned to a soil health management system. The Soil Health Institute will assist in any way we can.