To make soil samples, you need to collect soil from specific locations and depths, typically using an auger or spade, ensuring you gather enough representative samples from your chosen area.
Collecting soil samples correctly is crucial for getting accurate test results, whether you're checking for nutrients, pH levels, or soil health. The process involves carefully gathering soil from the top layer of the ground.
Here’s how you generally make soil samples based on standard methods:
- Prepare the Spot: Begin by removing any surface litter from the area where you plan to take the sample. This includes leaves, grass clippings, and other debris that aren't part of the soil itself.
- Collect the Sample:
- Using an Auger: Drive the auger to a plough depth of 15 cm and draw the soil sample. An auger helps you collect a consistent core of soil down to the desired depth.
- Using a Spade (if auger is not available): Make a 'V' shaped cut to a depth of 15 cm in the sampling spot using spade. After making the cut, slice a consistent layer of soil from one side of the 'V'.
- Gather Multiple Samples: To ensure your sample is representative of the entire area you are interested in (sometimes called a 'sampling unit'), you must collect at least 10 to 15 samples from each sampling unit. These multiple samples are then combined to create a single, composite sample for testing.
- Combine Samples: Place all the individual samples collected from one sampling unit into a clean bucket or tray. Mix these samples thoroughly to create a single, well-mixed composite sample.
This composite sample is what you will typically send for laboratory analysis. Collecting multiple samples and mixing them ensures that the final sample reflects the average conditions across the entire area, reducing the impact of small variations within the soil.
Proper sample collection depth is usually standardized (like the 15 cm depth mentioned) to represent the main root zone where plants actively take up nutrients.
