Soil Sampling should be carried out a minimum of every 4 years on combinable arable farms or for more specialist crops with specific requirements before each crop is crown. Field Advisers at Needham Chalks (HAM) are able to carry out all types of soil sampling from pH to P,K, Mg and also full trace elements as well as GPS Nutrient mapping. See below for a full list of services.

 

 

 

pH Soil Sampling

 

pH soil sampling is conducted by taking soil samples methodically across the field ever 1-2 acres and conducting on the spot samples. This is done by placing a few grams of soil in a test tube and mixing it with barium sulphate, de-ionised water and indicator and shaken. The barium sulphate ensures flocculation and precipitation of colloidal clay. The resulting coloured solution is compared with a colour chart to give the correct pH reading.

 

Test results are plotted on a field map so that any lime required can be applied in the right place and at the correct rate. Soil indicator solution is the only reliable method of measuring the soil pH however poor and patchy crops and the presence of some acid preferring weed species can be used as a rough indicator.