Potassium Availability of Fused Potassium Phosphates¹

Abstract

Synopsis Availability to plants of potassium in minus 35‐mesh fused potassium phosphates having low water solubility was equal to that in potassium chloride and sulfate. Increasing the particle size to −6+9 mesh decreased availability of the less soluble materials.

Nitrogen Availability, Nitrification of Fractions from Commercial Ureaforms

“…While the nitrification studies on ureaform fractions were run on samples ground according to a standardized procedure, the effect of granule size on the availability of fertilizers has been shown to be closely related to the surface area of the granules (2,11,12). This effect has been studied in nitrogen fertilizers, particularly for oxamide (77) and magnesium ammonium phosphate (4).…”

Comparison of potassium chloride, bicarbonate, and metaphosphate, and calcined orthoclase, as sources of potassium for white clover

“…A possible means for achieving this, however, might lie in the preparation of a frit or fusion mixture (Lunt and Kwate 1956;DeMent and Stanford 1959). Another, and probably more satisfactory, solution may well be found in granulating the salt crystals and coating with an inert substance, to slow down disintegration and solution under field conditions (Lawton 1961).…”

“…1942) and agricultural and laboratory experimentation (Jones and Rogers 1949;McIntire et at. 1953;DeMent and Stanford 1959;Thorup and Mehlich 1961), but so far it has remained mainly an experimental material because of technical problems associated with its production. A new low-temperature process recently announced by Scottish Agricultural Industries Limited (Anon.…”