To understand what is in your soil and what you will need to grow what you want, you’ll need to do a simple test first.
- A small spade or digging implement
- Well mixed soil samples taken from the areas you intend to use.
- A clear container
- Some clean water
- Some time
- A measuring ruler – in cm/mm works best
- A copy of a Soil Texture Triangle (Click here for printable copy)
- When we take soil samples, to get the best average results, we take them from several locations around our planned growing areas. To get good mixed sample(s) we dig in a few spots, to different depths with an average of 2-10 inches in depth.
- Then we can place amounts of the soil from separate locations into a clear glass or plastic container. Preferably with a lid.
- Samples need to be sufficient enough for you to see, so take about a 1/3- 1/2 by volume based on your container.
- Fill the container with clean, preferably distilled, water.
- Give the vessel a quick shake to mobilise the matter in the solution, a good stir will work. A lidded container ensures nothing else falls into the sample post mixing. But just covering it will suffice.
- Then place the vessel on a flat surface and wait for the particles to settle out. Typically the sand will settle first, then the silt, finally clays, which can take up to 24 hours.
- As each layer settles out, take a magic marker and draw a line to mark the top of the layer. These you will use later to measure the volumes using a ruler.
- After 24 hours, you should see layers have formed.
Using the measurements, we use mm’s(millimeters) or cm(centimeters), you can calculate the volume percentages of your soil make up, so x% clay, y% sand and z% silt.
So let’s create an example where we say that our clear bucket shows:
- Sand = 30mm
- Silt = 22mm
- Clay = 25mm.
We add these together to reach a total volume so 30+22+25 = 77mm
Next we need to convert these to percentages, so taking our example here, we say:
- %Sand = 30/77 x 100 = 39%
So we can say our soil is 39% sand.
We repeat this conversion for the remaining layers.
- % Silt 22/77 x 100 = 29%
- % Clay 25/77 x 100 = 30%
Now we have this information as a percentage, we can use it to determine our soil type by referencing it against the Soil Texture Triangle above. Once we do we can safely say we have X soil type and we can use this basic information to better plan for future planting success.