What is meant by soil biology? Isn’t soil just a bunch of minerals? The answer is no and your soil contains so many living organisms, most of which are not visible with the naked eye, but all are important for the soil’s ecosystem. The visible organisms are earthworms and small mammals like gophers, moles or voles, however the vast number of organisms are only visible with a microscope such as bacteria, fungi, nematodes, protozoa and more. What does all of this biology have to do with the health of my garden? Well the answer is without soil biology, your plants will have problems accessing nutrients like nitrogen and phosphorus, both essential for growth. What can be done to improve and increase your soil’s biological makeup? Well they need adequate organic matter, good aeration, proper moisture, and a fairly neutral pH. One of the easiest things to do to improve your soil biology is to work in some good quality compost. The compost will help hold onto moisture, help aerate the soil by maintaining soil porosity and supply nutrients to the microbes already living in your soil.
Another important practice that will help improve soil biology is to plant a cover crop in areas that you are not actively growing in. Cover crops can be planted in the fall and cut down in the spring, or grown in the summer and finishes in the summer. Don’t forget to inoculate your cover crops if they contain legumes and inoculate legumes you are growing for food, like bush beans or pole beans. The Rhizobium bacteria in the inoculant forms a symbiotic relationship with the plants’ roots and converts atmospheric nitrogen into a plant usable form, in turn the plant supplies the bacteria with carbohydrates needed to live. Any extra nitrogen the plant does not need is stored on the roots and can be used by the following crop.
If you are interested in reading more about soil biology, you can read our articles Weaving the Soil Food Web or The Dirt on Mycorrhizae.