Submitted to: Transactions of the ASAE
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/1/1996
Publication Date: N/A
Citation: Interpretive Summary: Cheese manufacturing in the United States produces about 9 billion gallons (34 billion liters) of whey (the liquid byproduct of cheese manufacturing) a year which contains about 35 million pounds (16 million kg) of phosphorus. Much of the whey is applied as fertilizer or disposed of by land application. The phosphorus is about 60% ortho phosphate, and the rest is in various organic forms. The results of studies on two sodic (high sodium and high pH) soils and three calcareous soils showed that at phosphorus applications of about three times that suggested for good fertilizer practices, the phosphorus from the whey did not move below 2 feet (0.6 m) in these soils. There was sufficient precipitation and adsorption of the whey phosphorus to avoid groundwater pollution at the rates applied.
Technical Abstract: Whey from cheese made using phosphoric acid (acid whey) contains up to 1200 mg total P per kilogram of whey and cultured cheese wheys (sweet whey) contain up to 500 mg total P per kilogram whey (about 62 percent ortho and 38 percent organic P). Much of the 34x10(exp9) L [9x10(exp9) gallons] of whey produced in the United States each year is applied to the soil. To determine P movement from whey applied to sodic and calcareous soils, ortho and organic P concentrations and movements were measured in four soils treated at various whey application rates. Bicarbonate extractable and saturation paste extract, ortho and organic P were measured with depth. Application rates of up to 1050 kg P per hectare from acid whey on sodic soils and up to 750 kg P per hectare from sweet whey on calcareous soils were used. Bicarbonate-extractable ortho phosphate did not move below 0.4 m in the two sodic soils by the end of one growing season. Neither saturation extract, nor bicarbonate- extractable, ortho or organic P moved below 0.6 m on the Portneuf soil or below 0.3 m in the Nibley soil by the end of two growing seasons. Even though the wheys used contained up to 42 percent organic P, these soils retained these high P additions for at least short periods of time. This data also suggests that the winter applied whey-P is no more mobile than the P applied during the growing season.