SOIL SAMPLING
Below you will find a guide on how to provide us with the best soil sample for testing.
Soil Sampling Process
Step One:
Individual cores of uniform size and depth collected from throughout the sampling zone or area should be composited in a clean, plastic bucket. A proper sample is a core taken from the surface to a depth of 15cm.
Step Two:
Mix these cores thoroughly and put homogeneous sub-sample into bag. Label the bag clearly and use this same information and identification on the soil test information form.
Step Three:
Follow the sampling grid guide below, avoid unusual spots, and try to obtain a well-balanced, representative sample from each point.
Soil sampling tools
There are two important requirements of a sampling tool. First, it must permit a uniform slice to be taken from the soil surface to a desired depth. Second, it must collect the same volume of soil from each sample site. A soil auger is the best tool for obtaining soil samples.
You need a total bulked sample of about 400g to send to the laboratory for full soil analysis.
If a soil auger is not available, a small shovel, trowel or a spade can work satisfactorily when used properly:
Step One:
Dig out a spadeful or two of soil to a depth of 15-20cm, smooth off one vertical edge of the hole.
Step Two:
Take a slice of soil about 1cm thick, with the spade. Using a trowel, cut a 1/2 core lengthwise from the centre of the slice while it is still on the spade.
Step Three:
Put the core in a bucket to be mixed with the other cores from the designated sampling area.
Soil Sampling Technique
- Use an auger (or narrow trowel) to 15 – 20 cm depth for field crops
- Have ready a labelled, clear, strong plastic bag with seal (zip lock)
- Make sure that you remove obvious contaminants like straw trash or stones
- Take clean core subsample (B)
- Either:
- If total core samples collected are too large for sample bag, place core samples in a bucket and mix thoroughly
- Check again for contaminants (weeds, roots, straw, sticks, worms, stones etc.)
- Check that bulked sample is sufficient (200 – 300g)
Information
Include the following information for each sample:
- Organisation name
- Sample ID ( e.g. EM00123 )
- Name of the field sampled
- Grid Location (GPS, What3Words or map reference preferably)
- Date of sampling
- Previous crop
- Intended crop