Pasture Management
for
Horses

Soil Sampling

You can sample the soil in your paddock and have it tested by a laboratory for pH and nutrient status. There are testing kits available to test soils yourself but do not expect these to give you more than a rough guide. These kits cannot compare to a laboratory analysis.

Sampling Technique

The laboratory that will be testing your sample may give you instructions on how to sample your paddock, and these should be followed. In the absence of any instructions, use the following guidelines.
Reasons for a Sampling Technique
The soil sample you will send to a laboratory will be relatively small, possibly about a mug full. It will be necessary to follow a technique to ensure that this sample is representative of your paddock.

What do you Need?

You will need a bucket to hold your soil, and a either a trowel or an auger to sample the soil to a depth of about 6" (150mm). You may be advised to use a tool that can be pushed in the ground to remove a core of soil but satisfactory samples can be taken using a trowel.

What do you do first?

You may have only one paddock that you wish to sample but it may contain more than one soil type. Before you start sampling, look at the paddock for obvious changes. Part of the paddock may relatively flat while the rest has an obvious slope, or there may be an obvious change grass species suggesting that part of the paddock is in-fact different to the rest. Treat these areas if they were separate paddocks, then if the soil analyses are different, they can be limed or fertilised separately. Obviously these areas need to be large enough to be worth treating separately.

Which areas of the paddock should not be sampled?

Avoid areas where livestock may have congregated and their droppings and urine will have altered the nutrient status. These areas will include the area just inside the gate, around a water trough, close to the field shelter, around trees, or beside a hedge offering shelter.
Other areas to be avoided will possibly include the site of an old muckheap.

What times should be avoided?

Do not sample within two months of applying fertiliser as this will give an unrepresentative result.

How should the samples be taken?

Walk on a zigzag pattern, taking samples from about 25 spots in the paddock. If using a trowel, first dig a hole to the depth of the trowel, then use the trowel to take a thin slice off the side of the hole to a depth of about 6" (150mm), and put this in your bucket.
When you have done this in 25 spots, you are likely to have much more soil in your bucket than the laboratory will require. It is important that this soil should be mixed extremely well before removing the amount required. This is called sub-sampling.

How often should a paddock be tested?

This will depend on texture of your soil. As a rough guide, a light soil should be tested every three years, and a medium to heavy soil every five years.