No matter your nutrient regimen, your plants won’t succeed with poor soil structure; there are several key biological processes in plant and root growth that are aided and facilitated by strong soil structure. Air flow and moisture retention are imperative to good soil, and there is an ideal balance. You want media that will hold moisture, but at a mix that still allows for good drainage and airflow; just as you want a material that will allow for good airflow without increasing the drainage factor. With a poor structure, your plants are prone to root rot as well as a diminished rate of nutrient uptake and root size itself. There are typically three classes of particulates that make up soils: clay, silt, and sand. Clay particles perform extremely well for moisture retention but allow for little to no airflow. Sand on the other hand provides an exceptional airflow but fails to retain moisture at the levels needed for growth. Silt performs reasonably well in both retention and airflow, but it can only hold a limited amount of nutrients. The ideal mix is a Loam soil consisting of 20% clay, 40% sand, and 40% silt. This allows for a structure that efficiently holds moisture and allows air to pass through easily. If you’re unsure of your soil, there is a simple way to test its composition:
[You'll need a glass jar and some dish soap for this test]
- Take your glass jar and fill it about halfway with the soil that you want to test.
- Next, fill the jar with water until the jar is about 75% full.
- Add a tablespoon of your dish-washing detergent (liquid or granules) and close the lid.
- You'll now shake your jar vigorously for around three minutes in order to separate the particles.
- Set the jar on a flat stable surface where it can rest undisturbed for a few days as the particles settle back into place.
After a few days you will see three distinct soil layers—sand on the bottom, silt in the middle, and clay on the top. Organic material will usually float on top of the water. In general the darker the water, the higher the organic content in the soil.
If your percentages aren't in the ideal loam range, you can amend your soil by adding what's lacking until the mix is back on track and your structure is solid. To keep your structure's aggregates in place, adding Old Man Hu' will provide the soil with microbes and enzymes which bind the particulates in their ideal positions providing strength to the integrity of the soils now improved structure.