Interpreting Soil Test Results
Now that you have calculated the percentages of soil components, you have a general idea of your soil type and can choose plants that are well-suited to your native soil. If you’d like to get more scientific about it, consult the soil pyramid below to find the scientific classification of your soil based on the percentages of each layer.
Here’s how the soil tests I conducted came out:
- Farm Soil: (sandy loam) 70% sand, 20% silt, 10% clay
- Yard Soil: (sandy clay loam) 50% sand, 25% silt, 25% clay
In my experiments, it appears that the farm soil is sandy loam, while the soil in my yard is sandy clay loam. Both soils can benefit from improvement in both texture and fertility. Neither contain much in the way of organic matter, which fits with the low nutrient levels in my chemical soil analysis.
I was surprised to find that my home soil had such a high sand content, but I took the sample from an area that was amended with trucked-in soil during a grading project. Multiple samples – from different spots – would give a better overall picture.
As a comparison, I also did a jar test with some commercial potting mix as well (see photo at top), which is very high in organic matter and sand, making it perfect for the delicate roots on potted plants.
Improving Soil Texture
So what now? The good news is, adding organic matter will help all types of soil. It makes clay soils looser, helps sandy soils retain water and nutrients, and generally improves the texture and drainage of all soil types.
Organic matter such as compost, leaf mold, and humus add both soil particles and organic nutrients that balance out soil types. After amending your soil, conduct another jar test to see how your soil measures up, then add more or less organic matter next time to even out the ratios.