We have used compost since we began farming to build soil tilth, increase the microbiology of the soil (primarily fungi and bacteria – billions of them), provide a haven for earthworms, increase moisture and nutrient retention, and increase soil permeability to help the beds drain efficiently after downpours. This spring after a visit to nearby Ten Mothers Farm, we are utilizing shredded leaf compost from Brockwell Mulch near Carrboro as a one to two inch top layer before seeding or planting. For Gordon and Vera of Ten Mothers (proteges of organic farming guru, Eliot Coleman), the benefit of leaf compost on top is for moisture retention, nutrient enrichment, and WEED PREVENTION!
The practice also reduces significantly the amount of tilling required. Tilling brings weed seeds to the surface and reduces microbiota (the web of life). Also, over a course of several seasons, the compost works deeper into the soil and helps roots spread so that plants stay healthy in stressful situations such as drought and excessive heat.
Since we don’t use herbicides, we spend an inordinate amount of time weeding. Cover cropping with rye and oats helps with weed prevention as the shreds of mown grasses worked in the soil have an aleopathic effect on preventing grassy weeds from emerging for a few weeks. Yet, it doesn’t help with broadleaf weeds like chickweed and henbit. We also use landscape cloth to cover the soil and prevent weeds on crops like broccoli and peppers that will be in the ground for more than 60 days.According to Penn State researchers who spoke a few years back at a sustainable farm conference, we have 70% more varieties of weeds in North Carolina than Pennsylvania. We Tar Heels may be dirt poor, but we’re weed rich!
We make a smooth seed bed of the leaf compost and then have seeded carrots, radishes, beets, spinach, arugula, and Asian greens directly into the top layer of leaf compost. Today, we are broadforking to make the soil pliable and working the compost in deeper without tilling in order to make planting directly into the top layer of compost efficient and productive. Watering in the first few weeks is critical as well as protection against freezing nights with frost cloth.
Compost is an up-front expense in our farming practice, but if all goes well, reduce the amount of weeding, reduce our organic fertilizer inputs, reduce watering needs, and most importantly, provide a better yield of healthy, nutrient-dense, and tasty vegetables.