Fall is firmly in full swing, at least in most parts of the country. This means that frost or snow has caused the growing season to end. So what does that mean for our fields that have been harvested? Do we just leave them to sit fallow until the time comes to plant the new crop in the spring? I would say the answer is an emphatic no. There are things we can do to improve the soil during the off-season. You can do a few things: Mulch, green manure, or plant a cover crop. In this first edition of off season soil enrichment techniques I’m focusing on Mulch.
Mulching is any process where you would cover the soil. What we mulch with depends on your goals. There is a method called sheet mulching, that I prefer. What this consists of usually is the laying down of either newsprint or cardboard covered by a finer substrate. That is usually something like a chopped wood bark or wood chips. What this process does is create a physical barrier to protect soil from water and wind based erosion. This is accomplished by causing a break against wind and water. It keeps the elements from carrying off good topsoil. This is vital to being able to grow crops in the coming season. Another benefit to mulch is that it can protect seeds like garlic from harsh winter weather while allowing it to still germinate. It does this by allowing the soil underneath it to remain warmer than the unprotected surrounding ground. The final benefit I’ll talk about here is the providing of an environment for organisms that are beneficial to crops. Mulch can help earthworm populations as well as provide shelter for all sorts of critters in the soil food web. It helps to protect organisms like earthworms, which are very beneficial to the soil. They serve to decompose organic material like leaves, crop residue, and kitchen scraps. All of these will eventually become compost that will feed the soil and build nutrients for the plants to be grown later. Earthworms create what some call “black gold” which is in actuality the worm casings, an extremely nutrient rich manure like substance that can be used as a soil amendment. Finally earthworms burrow through the soil creating channels “pore spaces” in the soil that will allow water infiltration to be increased. This means that when it rains more water will be absorbed and be available for plants. This also means that less runoff will occur and that results in less top soil and nutrients washing away.
Mulch protects the soil, shelters organisms, rebuilds soil nutrient profiles, and it can be done cheaply compared to other methods of helping the soil. If done carefully one can even mulch for free (at least on the smaller scale). Collecting leaves and grass clippings from neighbors is an easy way to get cheap or free resources for mulching. Another less well known source of mulch is from your local municipality. Check your local recycling center for a mulch pile, most will let you fill up as much as you want and in my experience it is completely free. I urge every one to give mulch a try this fall and winter.