"One of the things we now better understand is just how important the living fraction of the soil is," said Chris Lawerence of the U.S. Department of Agriculture-Natural Resources Conservation Service. Lawerence joined us in the second episode of our podcast, 4 The Soil: A Conversation. "The organic matter [is] what makes dirt into soil. It's what differentiates topsoil –the darker, more pliable, more crumbly topsoil– from subsoil." When we are “4 The Soil,” we follow four core principles of soil health. The third principle is to maximize living roots. Maximizing living roots throughout the year fuels biological activity, aids nutrient cycling, and contributes to improved soil structure.
What does 'maximize living roots' mean?
"Science is helping us understand the way we feed the soil is not just by applying compost or manure or organic matter to the surface," explained Lawrence. "Those living roots of plants actually pump out food for microorganisms that live in association with crop roots."
This principle encourages growing plants with different rooting patterns and depths throughout the year (including crop rotation and diversity). By growing cover crops and other plants, we can help fuel biological activity among microorganisms and microbes essential to soil health. Microorganisms and microbes are crucial to building soil, and feeding them well creates a healthy ecosystem. For instance, root exudates (fluids emitted through living roots) help break up nutrients in the soil for consumption, similar to the gastric juices in our stomachs. Maximizing living roots also aids nutrient cycling between the plant root and the soil, which means the soil can absorb and store more essential nutrients like carbon, mineral nitrogen, and phosphorus. With the ability to cycle more nutrients, we also help improve soil structure. Good soil structure that is cake-like and sponge-like improves the soil's drainage, aeration, and water retention, too.
How do we maximize living roots?
"There's a very, very sophisticated symbiotic relationship between the life in the soil and plants," said Lawrence. "If we can keep living roots in that soil as much as possible throughout the year, keep something growing, that is an important way to feed the soil." Growing cover crops, the first principle of building soil health, helps maximize the presence of living roots. Diversifying and rotating crops (i.e., grasses, legumes, brassicas, and forbs), eliminating fallow, and dedicating space for native grasslands also aid in maximizing living roots. Minimizing soil disturbance and preventing soil compaction also allows roots to grow. The difference between tilling and no-tilling practices can be seen in farms across Virginia.
Join the movement! 4 The Soil is a campaign by the Virginia Soil Health Coalition 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.
