Soil Analysis

The NWF Soil Analysis Service enables accurate assessment of the correct levels of the most important nutrients that should be applied to grassland, arable and forage crops. The results provide insight on how to use fertiliser more efficiently.

Soil Analysis Results

Soil analysis is necessary to enable prediction of nutrient levels available crops, ensuring the correct additives can be made for optimum plant growth and crop protection.  Standard soil analysis includes pH, P, K and Mg. Trace elements can be included on request at an additional cost.

The available levels of the following can be accurately measured:

• Phosphorus
• Potassium
• Magnesium
• pH
• Calcium
• Sulphur
• Sodium
• Iron
• Manganese
• Copper
• Zinc
• Boron
• Molybdenum (Cobalt, Iodine of grassland)

Soil Sampling

The importance of care when sampling, the reliability of soil results, and the subsequent information that can draw from the results is dependent on the care and accuracy of the initial sample taken on farm.

Following three simple stages ensure the results are accurate:

Stage 1. Taking a representative sample of soil, from a uniformly managed area
Stage 2
. Supplying all relevant field and background information
Stage 3
. Correct packaging of the sample to avoid contamination, and immediate dispatch to the laboratory.

Soil samples should be taken on all fields at least once every 2-4 years. Soil where vegetables or other high cash crops are grown may need to be tested annually to ensure the most relevant and up to date information is available.

For arable and grassland P, K, Mg soil samples can be taken at any time of the year, provided fertiliser has not been applied in the past 4-6 months. Where lime has been applied, a period of 2 years should be allowed before a sample is taken for pH.

Fields of up to 10Ha (25 Acres) can be sampled as a single unit, providing the field is uniform (i.e. soil type, past cropping, lime and fertiliser usage etc.). If a field has been created through the removal of hedgerows, it is unlikely to be uniform and thus unsuitable for a single test.

Large fields and fields which are not uniform should be subdivided and each area sampled and labelled as separate. Ensure the equipment is clean (chromium plated or stainless steel auger, hand trowel or spade), and take a plastic bucket.

Soil Sampling Paths

When taking soil samples paths of individual samples should follow a carefully thought-out route across the field. The ‘w-pattern’ can be easily adapted to most shapes of field. Avoid areas which are not representative of the field as a whole, such as gateways, headlands, hedges, ditches, footpaths, fences, telegraph poles, bonfire-sites, or dumps of fertiliser, lime or manure.

We recommend 20 sub-samples, taken at regular intervals along the sampling path. This representative number is required even if the area is small.

Step 1 For each of the 20 sub-samples, remove the top 5cm (2”) of soil and discard away from the sample hole.
Step 2
Take a sample to a depth of 15cm (6”) for arable or 7.5cm (3”) for grass and place this into the plastic bucket.
Step 3
The 20 sub-samples should be mixed in the bucket, before filling a polythene bag with mixed soil (around 0.5kg (3/4lb) of soil).
Step 4
Seal bag securely and label it.

If there are problem patches within the field which need analysis, i.e. acid patches, do not mix with any other sub-samples, instead sample separately.

For more information call the NWF Trading Team on 01829 262 294 or click here