WASTE MANAGEMENT
PIH-25
pork industry handbook
COOPERATIVE EXTENSION SERVICE • PURDUE UNIVERSITY • WEST LAFAYETTE, INDIANA
Fertilizer Value of Swine Manure
Authors
Alan L. Sutton, Purdue University
Dale H. Vanderholm, University of Illinois
Stewart W. Melvin, Iowa State University
Reviewers
J. Ronald Miner, Oregon State University
E. T. Kornegay, Virginia Polytechnic Institute
Swine manure contains fertilizer nutrients that can be utilized to support efficient crop production and enhance soil chemical and physical properties. Thus, manure can be an asset to a swine operation when managed to maximize the use of the available nutrients for fertilizer. The purpose of this fact sheet is to provide the swine producer with pertinent information on (1) the fertilizer nutrient content of swine manures available for land application, (2) how to determine manure application rates and the need for supplementary fertilizer for maximum crop production, and (3) related management techniques for maximizing the fertilizer potential of swine manure on the farm.

Factors Affecting Fertilizer Value of Manure, and Recommendations for Application
The type and amount of nutrients in swine manure and their eventual availability to plants varies considerably from farm to farm. Some factors affecting nutrient value of manure are: type of ration fed to swine; method of manure collection and storage; amount of feed, bedding and/or water added; time and method of application; soil characteristics and type of crop to which the manure is applied; and climate.

Increasing levels of additives (copper, arsenic, etc.) and inorganic salts (sodium, calcium, potassium, magnesium, phosphate, chloride, etc.) in swine rations will change concentrations of these elements in manure. There is concern about the potential toxic effects of elevated concentrations of heavy metals and salts in soil and plants as a result of high application rates of manure to the land. Routine soil tests and manure analysis on your farm are recommended to monitor the balance of nutrients in the soil, especially on land receiving heavy manure applications.
Bedding and water that get into manure dilute its nutrient concentration, thus lessening its value per ton or gallon when applied to the land. Feed spillage, on the other hand, will increase manure nutrient concentration for land application. Feed spillage and inadequate agitation may cause sludge buildup and difficult removal in liquid manure systems.

The type of housing and/or waste handling system greatly affects the nitrogen (N) concentration of swine manures (Table 1). Major N loss occurs when manure is dried by sun and air movement or is leached by rain as would be the case in an open lot system. In contrast, comparatively little N is lost from manure in a completely covered feedlot when a manure pack or liquid pit storage system is used. Loss of N is greatest in long-term treatment or storage systems such as oxidation ditches or lagoons.
Table 1. Approximate nitrogen losses from swine manure as affected by handling and storing methods.	
                 Handling, storing methods	             Nitrogen loss*
	%
Solid systems	
  Manure pack	35
  Open lot	55
Liquid systems	
  Anaerobic pit	25
  Oxidation ditch	60
  Lagoon	80
*Based on composition of manure applied to the land vs composition of freshly excreted manure.