Increased Water Retention: Co-Benefits of Soil Health Series

Photo by USDA-NRCS in Gaining Ground video series at gaininggroundvirginia.org

Have you ever seen a field with standing water after a rainstorm, then dried up in the heat of summer? It might seem normal, particularly as we experience more extreme weather patterns. But what if the soil could retain more water, store it deeper, and use it when necessary? Healthy soils work like a sponge. Rather than becoming saturated in the rain, healthy soil is better able to absorb rainfall and save it for a drier time.

​We can help soil increase its water holding capacity by following the four core principles of soil health. Keeping the soil covered with cover crops, mulch, or even tree shade will help reduce exposure to sun. This cover shields water from evaporating too quickly, keeps the soil cooler and encourages beneficial bacteria and fungi to grow. Coverage also helps plants slow the flow of water, allowing it time to sink down deeper. This allows soil and nutrients to remain in place rather than eroding and running off in the rain. Maximizing living roots help aggregate the soil and create larger pores for water to move through. Beneficial fungi thrive on living roots, and they become the main pathway for carbon and nitrogen to cycle through the soil. Minimizing soil disturbance can also build up water holding capacity. Robert H. Spiers Jr. of Spiers Farm, LLC in Stony Creek, Virginia, describes how his no-till and low-till operation helped the soil thrive in a drought. During one of the hottest Julys on record, Spiers’ farm went 27 days without rain. Their acres of corn would not have survived 30 years ago, but because of their diligent cover cropping and soil care, their fields still produced 75 to 80 bushels. "It became very obvious that soil was the answer if I wanted to continue farming," said Spiers. Finally, energizing the soil with diversity enhances its water holding capacity. Diversity can look like introducing healthy livestock integration, in which livestock rotate regularly to allow pasture to regrow and roots to develop. This principle can also include rotations of different crops and integration of enterprises like pastured poultry and layers. Diversity focuses under the surface, too. Different roots hold and utilize water differently, and growing a variety of plants helps retain water. Diverse roots also attract a variety of microbes, bacteria, and fungi, which strengthen the soil structure and, therefore, influence the water holding capability. Even earthworms can help soil retain water. "They create large channels for water to infiltrate and penetrate into the soil," said Dr. Alan J. Franzluebbers of North Carolina State University and USDA-Agricultural Research Service on Episode 22-4 of our podcast, 4 the Soil: A Conversation. Following the four principles of soil health management encourages numerous co-benefits. Increased water retention can also help control erosion, build drought tolerance, and provide economic benefits through more efficient irrigation and potentially increased yields. Many living creatures thrive when building soil health –from microorganisms to humans.

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Join the movement! 4 The Soil is a campaign by the Virginia Soil Health Coalition and Virginia Tech to raise awareness of soil as an agricultural and natural resource. By caring for the soil, we can build healthier communities, stronger economies, and a more resilient landscape.

Highlighted Resources

• Gaining Ground video series led by USDA-Natural Resource Conservation Service

• What’s the value of soil health for nutrient management in Virginia? by Dr. Alan Franzluebbers

• Soil, Conservation and Place Project by Virginia Tech Center for Food Systems and Community Transformation

Photo by Virginia Cooperative Extension from Soil, Conservation and Place Project with Robert Spiers Jr. of Spiers Farm, LLC