Agriculture Reference
In-Depth Information
With this test, you're aiming for a 10:1 calcium to magnesium ratio, or 7:1 for grasses/
grains and for very sandy soil. The lower the ratio gets below 7:1, the more potential for
compaction and drainage issues, as well as poor microbial life and unhealthy plants. If
you see grass weeds such as crabgrass, it's probably because it's come along to help make
calcium available.
You're aiming for a 2:1 phosphate to potash ratio, or 4:1 on sandy soils. If they give
you the numbers as phosphorus and potassium instead of phosphate and potash, it's a 1:1
ratio you want, or 2:1 on sandy soils. The calcium to magnesium and phosphate to potash
ratio are the most important to balance, so worry about them first. You're also aiming for
a 1:1 potash to sulfate ratio. You may also get a few micronutrients tested. I don't worry
about correcting them until I've corrected the main ratios, because I've found some of the
micronutrients will fall in line when the main ratios are good.
A summary of the ideal ratios follows. Like the base saturation test, the specific amount
of each nutrient in the soil is often not as important as their relationship to each other.
