From Longman Dictionary of Contemporary Englishpotashpot‧ash /ˈpɒtæʃ $ ˈpɑː-/ noun [uncountable] HCTAa type of potassium used especially in farming to make the soil better
Examples from the Corpus
potash• Potash shortage is often an induced condition caused by too much nitrogen reducing the potash content to an unbalanced proportion.• This has led to a shift away from the traditional use of phosphate and potash.• Give a little extra nitrogen to blackcurrants and cooking apples; extra potash to gooseberries and red and white currants.• A suitable high potash alternative is tomato food.• Apple trees require plenty of potash and nitrogen, especially if the area is grassed over.• Spence's product was an ammonium alum which gradually displaced the potash alum which had been made principally at Whitby.• The hydroelectric scheme may involve the potash industry in an extra expense.• Soap was locally made from animal fat and lime mixed with potash derived from the burning of green bracken.Origin potash (1600-1700) pot + ash; because it was made by putting ash in water and letting it dry out in pots 