Soil Sampling - Save Money And Improve Water Quality!

It is a requirement of the Phosphorus Regulations (2006) that farmers must not apply chemical phosphorus (P) fertiliser unless there is a crop requirement, taking into account soil fertility status and the supply of phosphorus from the application of slurry or manure. The only way to find out the soil fertility status is to carry out a soil analysis - every four years.

With the dramatic increase in fertiliser prices for 2008, it is important to ensure that the type of fertiliser sown, best meets the needs of the growing crop. By taking soil samples and having them analysed, it is possible to supply only the nutrients which the crop requires. This will help optimise productivity whilst reducing the risk of nutrient leaching into waterways. In most cases soil analysis will also save you money.

The requirement of phosphorus and other nutrients can be determined from the results of a soil sample. For accurate results it is important that land to be sampled should not have received any fertiliser (chemical or organic) for at least three months. The size of area from which one sample can be taken can vary, but should not exceed four hectares. If the field size is less than this, samples from fields which receive similar management, may be combined in one sample.

A soil sample should be made up of around 25 sub-samples, which must be taken systematically throughout the field. This can be achieved by following the pattern of a letter ‘W’ and taking sub-samples at regularly spaced intervals. A representative sample of this is then placed in a labelled plastic bag which is provided with the soil auger. Soil augers can be pre-booked from your local DARD Office.

Soil analysis results will include the crop requirement for lime, and outline the phosphorus, potash and magnesium available in the soil. These results will then determine what type and what amount of fertiliser are required.

For more information on soil sampling or to obtain a soil auger, please contact Countryside Management Branch at your local DARD Office.