Spring is here and soils are slowly beginning to warm up. As they warm up, they become microbially active, feeding on carbon and recycling nutrients. Your goal is to optimize soil conditions so you can optimize biological activity, including soil microbes and critters that live in the soil. Remember, the soil sustains them and provides them with the resources they need to survive and hopefully thrive. And in return their activities keep the soil healthy and productive.
But as the season begins, think about a few key elements that are necessary to stimulate biological activity. Remember you can’t have a healthy soil without a quality soil, so you need to pay a bit of attention to the soil environment the microbes live in. And microbes appreciate many of the same benefits from the soil that crops do.
How do you know if you are doing the right things to keep soil healthy? And while adopting no-till and cover crops are valuable practices, without metrics you don’t know if you are improving the soil. I suggest paying attention to the following practices.
- What is the quality of the soil? Take a soil test and look at pH, EC (electroconductivity for salt content) and nutrient levels. Soil microbes require a near-neutral pH, low salt levels and an available supply of N, P and K to thrive.
- What is the structure of the soil? Microbes require oxygen, water and the soil at the right temperature. While you can’t do much about soil temperature, you want the soil to be porous with low bulk density and no compaction layers. Soils with high bulk density or presence of compaction layers limit air and water movement into and through the soil.
- What is the organic matter level in the soil? Organic carbon is an indicator of soil health, and soils should have 2.5% to 3% organic matter. This organic carbon is good for soil structure, and some of this carbon (passive) is food for microbes.
- Do you use no-till practices? Tillage is hard on soil structure and speeds up carbon loss. While reduced tillage protects from erosion, it is not as good for soil health as no-till.
- Planting high residue crops. Planting high residue crops, like corn and wheat, more often than soybeans builds organic matter. If you are in rotation with more corn and wheat and practice no-till, organic matter levels should be building.
- Do you use cover crops? Covers protect the soil, scavenge nutrients and add organic carbon back to the soil. However the roots of green, actively growing covers leak active carbon that feed the microbes.
Soil health is the result of how you farm and manage the soil. As you go to the fields this spring, what is the health of your soil? Take some time to assess it mentally and physically.
Agronomist Dr. Daniel Davidson posts blogs on agronomy-related topics. Feel free to contact him at firstname.lastname@example.org.