Potash in Agriculture

The major use of potassium sulfates is in agriculture as a fertilizer (97%). The other 3% is used in industry. Potassium sulfate accounts for about 5% of the potash industry. It is twice as expensive as potassium chloride and is only used as potash fertilizer where it performs better than potassium chloride. 

Uses Of the Stassfurt salts.—The magnesium compounds in the Stassfurt salts are used for the preparation of magnesium and of its salts. The potash salts are an essential constituent of many fertilizers used in agriculture, etc. 22 and potassium chloride is the starting-point for the manufacture of the many different kinds of potassium salts used in commerce—carbonate, hydroxide, nitrate, chlorate, chromate, alum, ferrocyanide, cyanide, iodide, bromide, etc. Chlorine and bromine are extracted by electrolysis and other processes from the mother liquids obtained in the purification of the potash salts. Boric acid and borax are prepared from boracite. Caesium and rubidium are recovered from the crude carnallite and sylvite. 

The American Potash Institute, Washington, D. C., compiles data on deliveries of potash for agricultural use by the principal American producers, and on imports of potash. Data are issued quarterly and annually. Tables of prices of farm commodities and fertilizer materials from published sources together with index figures on prices are published in the Institute s magazine. Better Crops with Plant Food (9),... 

Potassium losses from soils comprise crop removal, leaching, and erosion. The large potassium output by harvesting in agriculture must be balanced by potash fertilization in the form of potassium chloride or potassium sulfate. Compared with the amount of potassium absorbed by crops, the potassium content of soil solution is small. The potassium content in soil solution is dependent upon the water content of the soil, and can be raised by liming. Plants may remove potassium selectively from the soil solution indeed, during erosion the clay fraction with its high potassium content is selectively removed. 

Important Compounds and Uses Around the turn of the millennium, the total annual output of the world s potash industry including potassium sulfates and potassium products for industrial uses amounted to 30 million tons of K2O. Capital investment in the Soviet Union and Canada and the rapidly increasing use of fertilizers in agriculture in the 1960s and 1970s led to a steep increase in world potash production. Since 1980, the average annual increase in world potash production has been only 0.7%. 

Munson, R. D. 1980. Potassium Awiilability and Uptake, Potassium in Agriculture, Potash and Phosphate Institute, pp. 67-108. 

De Datta, S. K. 1985. Nutrient Requirement for Sustained High Yields of Rice and Other Cereals, Proceedings of Colloquium Potassium in Agricultural Systems of the Humid Tropics, pp. 97-120, International Potash Institute, Switzerland. 

Potash (sylvite, carnalite) Fertilizer in agriculture and potassium chemicals, (e.g., soaps, detergents, dyes, explosives). 

Major agricultural countries such as the US must import large amounts of potash to meet commercial needs. In 2008, imports of 5.8 Mt supplemented the 1.1 Mt of home-produced potash in the US. World reserves of potash are estimated to be approximately 250 billion tonnes. 

Sizing. In most flotation plants, flotation concentrates, after being dried, are sized into three fractions and each serves a specific agricultural market. The fractions are coarse-, standard-, and suspension-grades of muriate of potash. Typical screen analyses are presented in Table 6 other physical characteristics are summarized in Table 7. 

Some compounds of the s-block elements are important industrial chemicals, too. For example, more than 1.4 billion kilograms of K2 CO3 (potassium carbonate, whose common name is potash), is produced in the United States each year. This compound, which is obtained from mineral deposits, is the most common source of potassium for fertilizers. Fertilization with potassium is necessary because this element is essential for healthy plant growth. Moreover, potassium salts are highly soluble in water, so potassium quickly becomes depleted from the soil. Consequently, agricultural land requires frequent addition of potassium fertilizers. 

Evaporites are important sources of economic minerals that have been exploited for at least the past 6000y. For example, the evaporite mineral trona (NaHCOj -Na2C03 2H2O) was used by the ancient Egyptians to preserve mummies. Evaporite salts continue to be used for food preservation, construction, road deicing, and in industrial processes. The marine evaporites of Saskatchewan (Canada) are the world s largest source of potash (KCl), which is used as an agricultural fertilizer. In the United States,... 

Potassium is determined in the acetic acid as well as the lactic acid extract. The potassium values for biologically managed fields lie between 100 and 200 mg K kg soil, and are less than those recommended for conventional agriculture. Light soils normally have low values, and clay soils, which bind more potassium, have higher K levels. Potash fixation is also assessed according to Schlichting and Blume (1951, p. 84). 

Potash was made on a small scale in New England in the seventeenth century, and for two centuries American potash and pearlash, made by burning wood and leaching the ashes, were shipped to European countries, with incalculable loss to American agriculture (50). 

In an attempt to find out whether the presence of soda or potash depended on a specific difference in the plants which produce them or on the composition of the soils, du Hamel devoted many years to agricultural experiments, at his estate at Denainvilliers, on the culture of the common saltwort (Salsola kali), a plant used for the manufacture of soda ash. The final analyses of the ash of this plant proved that in the first year the mineral alkali still predominated, but that in succeeding years the vegetable alkali rapidly increased until finally, after a few generations, the soda had almost disappeared (50). In these experiments, he had for many years the invaluable and enthusiastic help of his brother, M. de Denainvilliers. In his eulogy of du Hamel in the History of the Academy of Sciences, the Marquis de Condorcet gave the following characterizations of the two brothers ... 

From 1878 to 1883 Nilson served as professor of analytical chemistry at the University of Upsala, but in his later years he taught at the Agricultural Academy at Stockholm. He found that the sterility of the calcareous moors of his native island was caused by lack of potash. After liberal use of kainite fertilizer, recommended by Nilson, Gothland Island began to yield good crops of sugar beets (6). 

In an effort to stabilize earnings in the cyclical nitrogen products market, Potash Corp has decided to emphasize industrial sales (rather than agricultural sales) from their North American production base and use low-cost production in Trinidad to supply the North American fertilizer market. Since initiating this strategy in 1997, they have increased industrial sales of nitrogen products from 25% of production to 55% of nitrogen sales in 2001153. 

Potash Potassium hydroxide (K2C03). Potash is used primarily as an agricultural fertilizer, soap and in glass manufacturing. 

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