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United States Department of Agriculture

Agricultural Research Service

Title: Phosphorus Extraction As Affected by Soil Organic Carbon Increases Following Whey and Manure Applications

item Robbins, Charles
item Freeborn, Larry

Submitted to: Western Society of Soil Science
Publication Type: Abstract Only
Publication Acceptance Date: April 9, 1998
Publication Date: N/A

Technical Abstract: Recent increases in confined feeding operations, specifically dairy and swine, in the Intermountain West require disposal of ever increasing quantities of manure and whey. Both materials add large quantities of P to the application sites over time. Many states are starting to regulate how and when these wastes are land applied. Most of the data available for making those decisions were not obtained on calcareous soils or in arid or semi-arid areas. A calcareous topsoil and a freshly exposed subsoil were fertilized with inorganic fertilizers, dairy manure and cheese whey. Twice as much P was added with the whey as with the manure. Nearly equal amounts of organic matter were added with the whey and manure. Organic matter added with the whey did not influence soil Organic Carbon (OC) concentrations while that added with the manure doubled the subsoil and increased the topsoil OC concentrations. Changes in OC and ortho-P and organic-P concentrations in saturation extracts and sodium bicarbonate extracts were measured once or twice a year for eight years. All four P measurement concentrations were linearly related to soil OC concentrations rather than the amount of ortho, organic or total P added to the topsoil or to the subsoil. These results suggest that organic waste application rates to arid calcareous soils should be based on soil test results rather than P application rates.

Last Modified: 4/1/2015
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