How To Improve Garden Soil
by Valerie Palmer
Life creates life... especially in the garden!
Soil life eats and decomposes organic matter, which causes minerals to be released in a form that plant roots can absorb. In addition to this fertilizing effect, all the organic waste helps the texture of the soil - loosening hard-packed clay or binding loose, sandy soil. Humus gives the soil its necessary sponge-like texture that allows air circulation and moisture retention.
For these natural processes to occur, the soil life needs fresh supplies of food. Without this fuel, earthworms go away and the minerals and nutrients get 'locked' in soil particles, not available for plant growth. Insect pests and diseases take over the weakened plants. Pouring on the chemical fertilizers won't help because they don't contribute to soil texture and flourishing soil life.
A very complex natural process of soil chemistry is oversimplified here. The intention is to only to highlight the essential need for a continuous and generous addition of organic matter to all garden soil. What follows are suggestions for actions to take to feed the soil.
One method, of course, is to chop garden residues and weeds into the soil after a crop is harvested. Also, there's the option to haul in compost, in packages or in bulk when available. If there are processors in your area, (such as canneries or cider mills), often they will have waste organic material for the taking. Nearby farms usually welcome removal of animal manures: cattle, horses, chicken and rabbit. Any hay or straw used as mulch can be chopped in, along with leaves and lawn clippings.
A couple of notes:
- You can grow green manures in a rotation (an early green manure followed by a late-season planting of produce, or a late cover-crop following an early summer harvest like lettuce and peas) so that even if you have a small garden you will have a harvest crop as well as a cover-crop every year.
- Green manuring can be accomplished by any gardener regardless of powered machinery. However, a rotary tiller is definitely easiest. They can be rented.
Here are some suggestions for home garden cover-crops.
- Use legumes such as soybeans, peas, vetch, and alfalfa. They will 'fix' nitrogen from the atmosphere when you use 'inoculated' seeds that are attractive to a certain kind of microbe. Also, some legumes are vegetables, providing both a food and a green manure with the same crop.
- Plant ryegrass for a bulky, hardy crop that grows quickly. An annual variety is best, so that a late-summer crop will die back during winter allowing easy tillage in spring.
- For extremely poor soil, buckwheat is recommended. It will grow quickly and choke out weeds as well. Sow buckwheat for a main summer crop, after harvesting lettuce, etc.
The benefits to the soil of using cover-crops can't be overstated. In addition, there are other advantages: they help control weeds, they attract bees, and the carpet of green makes the garden look good right up to snowfall.