One of the four soil health principles is to keep the soil covered as much as possible. Mulches, cover crops, and even the vegetation of the crops themselves can help cover and protect garden soil. When soil is covered, valuable soil organic matter and nutrients are held in place and protected from wind and water erosion. Soil cover reduces soil evaporation rates, keeping more moisture available for plant use. Soil cover helps maintain a more moderate range of soil temperatures too, keeping soil warmer in cold weather, and cooler in hot weather. Coverage can also reduce soil compaction and crusting, which  improves plant growth and germination. Soil coverage suppresses weeds by limiting the amount of sunlight available to them, and it provides a protective habitat for the soil food web beneath.

Soil conservationists check moisture and soil health at a local Marion County urban farm.

Mulches such as leaf compost and straw at the SWCD Demo Garden.

A cereal rye cover crop, crimped and tarped, to use as mulch before sweet potatoes.

The sweet potato vegetation, in addition to the cover crop mulch, does a great job of soil coverage.

Dead cover crops in-situ can provide great inexpensive soil coverage.

The addition of leaf compost to the cover crop mulch provides a more full coverage to protect the soil through the season.

Compost as a mulch can work great with direct seeded crops too. The more that the soil is 100% covered should “mellow out” the soil and make it even more plantable.

Mulch decomposes and even more quickly when soil health is in good shape due to active biology. This spinach bed had an inch of compost applied as mulch in the early spring at planting. After two cuttings and a couple months, the compost has decomposed and bare soil is exposed. It is time to apply more mulch to keep the soil protected. Next year, the SWCD Demo Garden goal is to never get to this point where we can see the soil. That means more mulching up front, reapplications, continuing to grow mulch with cover crops, and being more attentive to keep 100% coverage.

Mulched up and ready to plant again! Keep it covered!