This soil deficiency correction and crop nutrient offtake calculator is made for farmers and crop nutrition advisors in England, Wales and N Ireland. It enables a quick calculation of the phosphate (P₂O₅) and potash (K₂O) offtakes by most UK crops at harvest. Simply enter the crop details and yield, click “calculate” and the nutrient offtakes (and fertilizer recommendation) appears. If the soil Index is below the target level, more nutrients will be required to compensate for both offtake and buildup of soil fertility, and vice versa. The App can be freely downloaded from the PDA website.

Potash Development Association (PDA) is an independent organisation formed in 1984 to provide technical information and advice in the UK on soil fertility, plant nutrition and fertilizer use with particular emphasis on potash. See also www.pda.org.uk.