This is the continuation of a web post from last week explaining how to test the health of your soil by burying a pair of cotton briefs. Catch up and learn how you can join the experiment at Cotton Brief Challenge Part 1.
For those of you who are interested in the soil health of your garden, pasture, or production field, we have a few guidelines for you to consider. According to our friends at the U.S. Department of Agriculture Natural Resources Conservation Service (USDA-NRCS), there are four basic principles to follow to improve the health and sustainability of your soil.
1. Use plant diversity to increase diversity in the soil.
Just as we need variety in our diets to stay healthy, so do soil microbes. Varying the plants we grow in our gardens or fields improves the health of our soil. Consider rotating crops each year and multiple cropping such as growing cool season crops in the spring and/or fall as well as warm season crops in the summer.
Use cover crops that incorporate legumes (peas and beans) because they fix nitrogen in the soil. Don’t forget to include deep-rooted plants like daikon radish that can break up compacted soil and open up spaces for oxygen and water.
2. Disturb soil as little as possible.
“Tilling soil,” in the words of the USDA-NRCS, “is the equivalent of an earthquake, hurricane, tornado, and forest fire occurring simultaneously to the world of soil organisms.” It disrupts the soil microbes and seriously ruins their habitat. Tilling breaks up soil aggregates which then reduces infiltration of water and leads to compaction.
Soil aggregates are groups of soil particles that bind to each other more strongly than to adjacent particles. Their stability is highly dependent on organic matter and biological activity in the soil. It makes sense that aggregate stability increases as biological activity increases. The soil microorganisms help create aggregates and use them as habitat.
Aggregate stability is also critical for water infiltration, root growth, and resistance to water and wind erosion. Protect your aggregates!
3. Keep plants growing throughout the year to feed the soil.
Living plant roots secrete sugars that are the first choice of food for soil organisms. The root sugars are the most easily accessible food for soil microbes, followed by dead roots, and then plant residue on the soil surface. By keeping plants growing all year you are providing easily accessible food. This increases microbe populations and helps them cycle nutrients that then become accessible to living plants!
4. Keep the soil covered as much as possible.
The first and most obvious reason to keep the soil covered is to protect soil aggregates from the erosive power of raindrops. According to Jason Warren of the Oklahoma Cooperative Extension Service, raindrops are similar to bombs that hit the soil at velocities of up to 30 feet per second.
Without plant cover to break the impact of rain, a single raindrop can splash a soil particle up to three feet away. These loosened soil particles may then be carried by water flowing over the soil surface. This is how field erosion carries away the foundation of your farm, your topsoil.
Another reason to keep the soil covered with living plants or plant residue is to suppress weeds early in the growing season until the plants you want to grow are tall enough to compete. Plus, keeping the soil covered keeps the soil moist. In times of drought, you can use all the extra moisture you can get!
While you are waiting to dig up your cotton brief experiment, or if you are just thinking about improving your soil health, try finding ways to incorporate these four basic principles into your farm or garden plan!
Information for this post originated from:
Farming in the 21st Century, a practical approach to improve Soil Health. United States Department of Agriculture Natural Resources Conservation Service September 2010
Jason Warren, Oklahoma State Univesity, Oklahoma Cooperative Extension Service
Use hashtag #SoilYourUndies to spread the word about the Cotton Brief Challenge!