a. Role of Potash in Plant Physiology

Potash, in the form of potassium cations (K⁺) helps to regulate many important biochemical processes, including photosynthesis. Potash improves crop vigour and increases resistance to drought, frost and disease. It is necessary for straw stength and helps to reduce lodging in cereal grains, especially for crops which receive heavy nitrogen applications. Plants need potash in large amounts - more than any other nutrient, with the possible exception of nitrogen.

b. Source of potash

All of the potash for plant growth comes ultimately from rocks and minerals. Potash is an important element in the earth's crust. It makes up more than 2% of the mass of crustal minerals.

Phosphorus ores occur in sedimentary deposits of soluble salts, usually with sodium chloride. Potash fertilizer is mined and processed at Sussex, N.B., but most of the potash used in North America comes from the vast underground reserves in Saskatchewan.

c. Potash use in soil fertility management

Potash is the third fertilizer nutrient. North American farmers routinely use large amounts of potash for crop production, though less than for either nitrogen or phosphorus. Both fertilizer and manure potash is highly soluble, and, therefore, readily available for plant uptake.

d. Nutritional problems with use of potash.

Fertilizer and manure potash presents little or no environmental risk; however, excess soil potash can be a problem in livestock nutrition. When ruminant livestock consume high-potash feeds they may suffer nutrient imbalances that can cause serious health problems. Dairy cattle, in particular, are prone to ill-effects of high potash diets.