Laura Lengnick, PhD Soil Sciences, Director of Sustainable Agriculture at Warren Wilson College shared the following four basic practices for soil health at a presentation to the Black Mountain Community Garden.
Keep it covered.
Keep a dead mulch such as straw, pine straw, leaves, etc. on the soil surface or create a living mulch by densely planting crops so that mature leaves overlap. Lengnick shared that this technique is particularly helpful because the leaves create a carbon trap, making photosynthesis more efficient and preventing weed seed germination.
Disturb as little as possible.
Tilling soil dramatically disturbs soil health. Soil disturbance encourages weed seed germination, disturbs the billions of occupants living in the soil and interrupts the mineral cycle.
Keep it right side up.
Healthy Soil has large concentrations of aerobic bacteria in the top 3 to 6 inches, gradually shifting to anaerobic bacteria the deeper in the soil structure. There are as many as 1 billion organisms in 1 tablespoon of good soil. In general we want to promote aerobic environments, said Lengnick. We want to maintain the gradient from aerobic to anaerobic environment. When we turn the soil, healthy topsoil will die, which takes a while to recolonize.
Feed diverse organic materials.
In other words, like us, soil needs a balanced diet. In the case of soil we need to feed it carbon rich compost, manures and a mix of nitrogenous and carbonaceous cover crops such as legumes mixed with grains in a 70 to 30 percent ratio.
Healthy soil is the immune system of your garden. It can reduce soil born diseases, provide a better home for beneficial organisms, store, protect and even produce nutrients, and detoxify harmful substances. Healthy soil is 50% space. A small increase in soil tilth creates a large increase in water storage capability. Follow these simple practices and your soil will produce healthy plants which will in turn produce healthy people.
Submitted by Diana McCall, coordinator of the Black Mountain Community Garden and a lifelong gardener.