Last Year’s Stalks Are Not Organic Matter

The title is correct. The residue from last year’s harvest is not organic matter. Neither is manure or leaves.

They’re organic material. It seems nitpicky, but there’s a vital difference between organic material and organic matter.

Essentially, organic matter is organic materials that have been broken down and decomposed by microorganisms in the soil. The important thing to know is that your crops can benefit from organic matter, but organic material is just trash with untapped potential. The key here is those microorganisms – without them, your organic material cannot be made into something beneficial for your crop.

Think of it like making a protein shake. You’re the crop, thirsty and ready to take in some nutrients. Organic material is the mix, and the water is the soil. To you, that protein powder is useless without being dissolved, just like the organic material is useless to the plant without being broken down. The microorganisms are just like the temperature of the water, controlling how fast the trash from last year breaks down, and having few microorganisms is like trying to dissolve something in extremely cold water.

So now that we know that the key thing is to have microorganisms to be able to break down the organic material into organic matter, we have to look at how to increase the amount of microorganisms. Here’s the two best ways to increase your microorganism count:

  • Reduce Tillage:
    • Every time you disturb the dirt, you’re disturbing those microorganisms’ environment. For microscopic living things, moving their environment just a few inches can create an uninhabitable space
  • Leave the Trash on Top:
    • A multi-year study at Iowa State said that in the first three years, there’s no difference in the speed of residue breakdown. However, after the first few years, Strip-Till and No-Till start to pull away, thanks to building those microorganisms. The moral of this story is that chisel plowing to mix all the residue isn’t helping anyone (except whoever you buy your diesel from), even in the first couple years.

The best part of these two ways to increase your microorganism count is that they will both reduce your expenses!