Mulch Increases Yields at Sustenance Farm

Backgrounder

Mulch has helped turn Sustenance Farm into one of the most productive farms in a hot, humid region of the southeastern United States. When Harvey and Nancy Harman moved to the farm a few years ago most of the topsoil had washed away and the soil was worn out. In less than two years they made the land productive again. Part of the reason for their success is that they use mulch.

The Harmans get the garden off to a good start by digging in lots of compost and making raised beds that trap rainwater in the field. Then they cover the soil with a thick layer of mulch made from old grass, weeds, or tree leaves. This layer is five to ten centimetres thick. If they are planting crops spaced far apart or in hills they separate the mulch so that a little circle of soil is showing, and plant the seeds there. If they are planting seeds in a row they separate the mulch so that there is a long row of exposed soil for planting. They always keep mulch on the soil. When the mulch gets thin, they add more.

If the Harmans don’t have enough mulch they grow more. They plant a cover crop such as buckwheat (Fagopyrum spp.), clover (Trifolium spp.), alfalfa (Medicago sativa), Sudan grass (Sorghum bicolor sudanese), or rye grass (Lolium spp.). When the cover crop gets tall enough they cut it by hand and use it as mulch.

Because they use mulch, the Harmans don’t need to do much weeding, and they don’t need to water often. The mulch shades the soil and plants from the hot sun so water stays in the soil. The mulch also reduces the number of weeds because it keeps out the sunlight that weeds need to sprout and grow. Also, they don’t have to buy fertilizers because the microorganisms and earthworms in the soil slowly break down the mulch to make new, fertile soil.

Let’s go through the steps again.

Spread the cut grass, weeds, or leaf mulch over the garden beds. Five to ten centimetres thick is ideal. Make small holes in the mulch, or divide it to make a row of exposed soil, and plant your seeds in the soil. Leave the holes or rows in the mulch open for the plant to grow well. When the mulch gets thin or when you see patches of soil through the mulch, add another layer, especially around young vegetable plants.

By using a thick mulch over the whole garden the Harmans don’t need to plow or re dig their garden plots. They have very little weeding to do. Their soil stays moist and cool even in the hot sun. Finally, as the mulch breaks down it becomes a natural fertilizer.