Manure Testing: What to Request?

Manure testing is necessary to make optimum use of manure while protecting water resources. This publication is a guide to providing information on a Manure Sample Submission Form for reliable interpretation of results.

Charles A. Shapiro, Extension Soils Specialist
Charles S. Wortmann, Nutrient Management Specialist

Tests Desired

The tests most frequently needed to optimize nutrient management are total and ammonium nitrogen (NH4-N), phosphorus (P2O5), potassium (K2O), pH, soluble salts, sodium, and dry matter content.

Nitrogen. Manure contains both organic and inorganic forms of nitrogen. Ammonium-N is the primary inorganic form in manure and is readily available to crops. Nitrate-N concentration is usually too small to affect management decisions, unless the manure is composted.

Organic nitrogen is the difference between total nitrogen and inorganic nitrogen. Organic nitrogen becomes available to plants as manure decomposes, with 20 percent to 50 percent of organic nitrogen available to the first crop after application. Much of the remaining organic nitrogen becomes available in subsequent years.

Phosphorus. Most manure phosphorus (about 75 percent) is in inorganic forms. Phosphorus analysis allows calculation of the most economical manure rates while avoiding over-application of phosphorus that can have severe consequences to surface waters.

Other tests. Tests for potassium, sulfur, zinc, and other nutrients may be useful. When manure is applied to meet nitrogen or phosphorus needs, other nutrients are generally adequate for soils in Nebraska. If liquid manure is applied to a crop through sprinkler irrigation, test for soluble salts or electrical conductivity to determine a management plan for avoiding leaf burning. For more information see EC778, Application of Liquid Animal Manures Using Center Pivot Irrigation. Information on soluble salt content or electrical conductivity is useful in managing anaerobic lagoons as “purple lagoons” associated with EC values of less than 6 mmhos/cm. When the surface of a lagoon has a purple color, the microbial processes are functioning well and the odor is less.

Report Information

Units. Specify if the results should be reported in pounds of nutrient per ton (spreader), per 1,000 gallons (tanks or umbilical cord), or per acre-inch (irrigation). This depends on your application method. Phosphorus and potassium should be reported in the oxide form (P2O5 and K2O) so their fertilizer value is easy to calculate.

Moisture. Reporting the results on an “as is” or “wet” basis allows a producer to determine the nutrient application rate without adjusting for water content.

Nutrient availability. Laboratories can estimate the amount of nutrients available in the first year, and the amount of manure nitrogen which will be available during following years. This is especially important for solid manures.

Application basis. Manure is often applied on a “nitro gen basis,” to supply enough nitrogen to meet crop needs. When soil test phosphorus is excessive, manure may be applied on a “phosphorus basis,” that is at a rate sufficient to match phosphorus removal by the crop.

Estimating Crop Available Nitrogen

The information requested is used to estimate the amount of nitrogen available to the crop from manure. Select the appropriate ammonium-N factor for the time of manure application and days until incorporation to enable an estimate of ammonium-N loss to the atmosphere. Indicate the type of manure and species as these affect organic-N availability. If manure applied in the past is similar to the current sample, give information on past year applications and the rate applied to estimate the amount of nitrogen available to this year’s crop from the previously applied manure.

Suggestions on how to interpret a manure analysis are given in NebGuide G1335, Determining Crop Available Nutrients from Manure.

Area Laboratories

Agvise Laboratories
902 13th St. N
P.O. Box 187
Benson, MN 56215
(320) 843-4109
Olsen’s Agricultural Laboratory
210 E. First St.
P.O. Box 370
McCook, NE 69001
(308) 345-3670
University of Nebraska
Soil and Plant Analysis Lab
153 Keim Hall
P.O. Box 830916
Lincoln, NE 68583-0916
(402) 472-1571
A&L Heartland Labs, Inc.
111 Linn Street
P.O. Box 455
Atlantic, IA 50022
(712) 243-6933
(800) 434-0109
Platte Valley Laboratories
P.O. Box 807
914 Hwy. 30
Gibbon, NE 68840
(308) 468-5975
Ward Laboratories
4007 Cherry Ave.
P.O. Box 788
Kearney, NE 68848
(308) 234-2418
(800) 887-7645
Midwest Laboratories
13611 “B” St.
Omaha, NE 68144
(402) 334-7770
Servi-Tech Laboratories
1602 Park West Drive
P.O. Box 169
Hastings, NE 68902
(402) 463-3522
(800) 557-7509

Manure Sample Submission Form

Client information:

Account: ____________________

E-mail: _____________________
Fax: _______________________
Analysis results to be communicated to:

__ Mail address
__ Fax number
__ e-mail address

If sent to e-mail address, would you like a:

__ pdf file
__ txt file
__ wks file
Sample names:

Sample collection date:

Send copy to: ________________
Tests Desired
__ Nebraska Minimum (Total N, NH4-N, Organic-N, P, K, moisture)
__ Standard lab analysis
__ pH, soluble salts, sodium
__ _______________________
__ _______________________
__ _______________________ Contact your lab for its ‘options’.
Report Information
__ lbs/ton
__ lbs/1000 gallons
__ lbs/acre inch
__ ppm or %

__ As received or wet basis
__ Dry matter basis
Nutrient availability:
__ 1st year availability only
__ Additional years

Estimate application rate on a:
__ Nitrogen basis
__ Phosphorus basis

Application rate units:
__ Tons/acre
__ 1,000 gallons/acre
__ Inches/acre
For the Estimate of Crop Available Nitrogen
Ammonium-N factors

Time of application
__ Fall
__ Winter
__ Spring
__ Summer

Manure incorporation

__ Immediately
__ One day later
__ Two days later
__ Three days later
__ Four to seven days later
__ Not incorporated

Sidedress application
__ Incorporated as applied
__ Sprinkler irrigated
Organic-N factors

Type of manure
__ Solid
__ Solids with litter or bedding
__ Composted solids
__ Stored liquid
__ Fresh, daily scrape

__ Dairy
__ Beef
__ Swine
__ Poultry – layer
__ Poultry – broiler
__ Turkey
__ Other:______________

Past year applications

__ Every year
__ Every other year
__ Every third year
__ Every fourth year
__ First time application Rate applied (if known):

Notes: ______________________

This generic manure sample form is provided by University of Nebraska–Lincoln Extension.


The authors would like to acknowledge the work of Richard L. Deloughery, former Water Quality Extension Educator, who was a coauthor of the previous edition of this publication.


Reference to commercial products or trade names is made with the understanding that no discrimination is intended of those not mentioned and no endorsement by University of Nebraska–Lincoln Extension is implied for those mentioned.

Visit the University of Nebraska–Lincoln Extension Publications Web site for more publications.
Index: Waste Management
Livestock Waste Systems
Issued November 2007