Wayne Sissel’s letter on soil health had some good points but needs more.
When he says, “We wanted healthy soils for those who tilled the soil 100 years from now,” he gets to the root of the problem. Tillage is the number one enemy of healthy soil. Organisms live where they do because the environment suits them there. When we till the soil, we change that environment in the same way as if we drain a lake or flood the land.
His ideas of a diverse rotation are excellent. But spraying chemicals has been proven a better way to preserve soil life than tillage when moving on to a different crop. We’ve been flying on cover crops for ten years and killing them with roundup. We haven’t used full-width tillage for 35 years. When I dig up a foot of seed trench I find fifteen earthworms in that foot.
We still need to be careful with chemicals, of course. Phosphorous fertilizer is deadly on mycorrhizal fungi, for instance. Mycorrhizae grow into plant roots and make phosphorous available that is otherwise tied up in the soil.
Farmers and politicians both seem to have trouble resisting the urge to “do something.” Tillage tools and subsidies and regulations destroy self interest. If we humans and soil inhabitants were simply left to do what we do best without interference, maximum efficiency would be maintained.