Soil performance generally improves when the complexity, or diversity, of the soil biological community increases. There is a limit to the amount of diversity that is economically and agronomically beneficial, but trying to increase diversity may be a useful way to manage soil biology. The next few pages will describe common ways to encourage healthy soil biology, and explain why some farm practices affect soil organisms. If you ask others for suggestions, keep in mind that what works in one place might not work in another. To manage the soil biological community, be a careful observer of the changes on your farm.
Most soil organisms rely on organic matter for food.
Each source of organic matter favors a different mix of organisms, so a variety of sources generally supports a variety of organisms. Maximize crop residue Crop residue is a convenient and valuable source of organic matter. Corn harvested for grain will grow 3 to 4 tons of surface residue per acre and 1 to 2 tons of root biomass. Dense, sod-type crops produce generous amounts of root biomass. Soybeans generate notoriously little surface residue.