The British Potato Council has launched a nutrient calculator on its website.

The interactive programme provides detailed individual field recommendations for nitrogen, phosphate, potassium and magnesium by assessing specific field information like soil index, previous cropping, variety being grown and length of growing season.

BPC agronomist Dr Rob Clayton said the calculator is quick and useful provided the information it receives is accurate.

'Crucial to the whole process is knowing individual field soil index for P, K and Mg along with cropping and weather records for nitrogen,' he explained. 'And account should be taken of organic manure, which is high in nutrients, before applying fertiliser to crops this year.' Those without internet connection can use a series of BPC advisory leaflets. To obtain copies Tel 01865 782270.