Natural availability of potassium in Polish soils and its uptake by various crops are examined on a regional basis. Potassium requirements of the main agricultural crops (wheat, rye, barley, oats, triticale, maize, potato, sugar beet, oilseed rape and grass for haymaking) are considered in view of the element's content both in farmyard manure and in chemical fertilisers; their use and the overall balance of potassium available for plant uptake in individual regions are shown in maps.
