Roots or Iron

This appeared in the March 3, 2022 edition of The Fish Wrap.

Everyone agrees that soil compaction is bad. Water won’t penetrate, so plants thirst while the water runs away and erodes. It’s hard to plant into, and hard for plant roots to grow through. Even air can’t get through, which creates an anaerobic environment. The best way to reduce compaction is to not create it in the first place, but we don’t live in a perfect world.  Some turn to cover crops and their roots to alleviate compaction while most will pull out the iron to do tillage instead.  Depending on conditions and practices used, tillage can create more problems than it solves.

Everything creates compaction to some degree, from a raindrop to a 50,000lb tractor.  Compaction layers can occur at the very surface, like from rain, and can occur over 2-3 feet deep from heavy axle loads.  While the compaction near the surface can be temporarily remedied with more tillage, the deep compaction can only be reached by roots.

Healthy, biologically active soils will have structure, held together by the mucilage of all the squiggling organisms living in the soil.  Keeping the soil covered all the time with living plants will keep roots growing deep into the soil, not only drawing water and nutrients up, but eventually decaying and leaving passages behind for water and air to infiltrate.

Mother nature knows how to prevent compaction, and can even alleviate it on its own in time, but humans are impatient and live on a different time scale.  So when we create compaction, we turn to either roots or iron to fix our problem.   Minimally invasive forms of tilling like broadforking or sub-soiling without disturbing the whole surface work well. One of the favorite plants to alleviate compaction is the mighty daikon radish that will punch large holes into tight soils.