Manure management has become an important topic because of its environmental implications.
However, economic and agronomic opportunities exist with little risk to the environment if
manure is applied to the land properly.
Manure as a Fertilizer
Like any fertilizer, it is important to know what substances are present in the manure, in
what form, and in what amounts. These substances should be monitored to avoid build up in
the soil to excess or toxic levels. This information is available from a laboratory manure
analysis and should be monitored by soil testing where manure has been applied.
Nutrients in manure exist in two forms: organic and inorganic. Since only inorganic forms
of nitrogen and phosphorus are available to plants, only a portion of the total nutrients
can be utilized in the year of application. The organic forms must first be converted to
an inorganic form (mineralized) which occurs naturally in the soil. This can be
advantageous for the crop because not all of the nutients from manure are immediately
available. The slow release of nutrients minimizes possible crop injury and prevents
excess nutrients from being lost before plant uptake occurs. Availability of manure
nutrients to the crop is dependent on the organic/inorganic makeup of the manure. With
nitrogen, three different measurements are given in a manure analysis:
- Total Kjeldahl Nitrogen (TKN) is the total amount of organic and ammonia nitrogen in the
sample.
- Ammonia nitrogen (NH3) is the amount of inorganic nitrogen that is readily converted to
plant available forms.
- Organic nitrogen is determined by the difference between total nitrogen and ammonia
nitrogen.
The general rule of thumb for nitrogen mineralization from manure is to expect 25-30%
of the organic nitrogen to be available to plants in the first year, with the remainder
becoming available during the next three years at a decreasing rate. Soil testing should
be conducted to confirm the actual amount of available nitrogen in any specific situation.
When considering application rates of manure based on nitrogen content, consider the
amount of readily available nitrogen (ammonia) relative to the amount of gradually
available organic nitrogen. In some cases, it may be necessary to add a starter fertilizer
to ensure the crop has enough nutrients available during its early growth stages.
Field and laboratory methods of manure analysis are available. Field test kits allow for
immediate estimation of nitrogen content and should be checked against a laboratory
analysis first. Manure analysis from an operation should change very little from year to
year if there are no major changes in feed ration or manure storage. Nutrient content of
manure samples may vary greatly if not thoroughly agitated, since solids usually settle
out during storage.
Sampling manure as close to time of application as possible provides the most accurate
reading of nutrient levels in manure. However, this practice is limited by the turnaround
time to receive a laboratory manure analysis to adjust current application rates. The
previous year's manure analysis can be used and the application rate adjusted based on a
current soil test.
Manure Sample Handling Instructions
- Half fill enclosed plastic jar with manure and close lid
tightly.
- Place jar in plastic bag and close with twist tie.
- Place plastic bag containing jar of manure in packing box.
Store in a cool place until shipping.
- Contact the laboratory of your choice for shipping
information.
- Place cheque made out to the laboratory performing the
analysis along with an information sheet with your name, address and type of manure in the
packing box.
- Ship to laboratory as quickly as possible (by courier,
prepaid).
- Be certain that sample spends no more than
two days in transit. A courier service can provide
delivery in less than two days. The mail service frequently does not. If sample must be
stored before shipping keep refrigerated.
Manure Analysis and Costs
Manure can be analyzed for several components, some of which have more agronomic
importance than others. Manure analyses of these components fall into one of three general
categories:
- Top Priority - % moisture/%dry matter (DM), Total N,
ammonia/ammonium-N, P, K;
- Secondary Priority - E.C. (total salts), pH;
- Low Priority - S, Na, Ca, Mg, total micronutrients (Cu, Mn,
Zn, Fe, etc.)
These constituents exist in relatively low levels in
manure and are not completely or immediately available for plant uptake.
Following is a list of available laboratories that conduct
manure analyses. This is not necessarily a complete list and Manitoba Agriculture, Food and Rural Initiatives
is not promoting one laboratory over another by including some laboratories and failing to
include others. Costs for manure analysis can vary from $20 to $85 per sample depending on
the laboratory and the type of analysis conducted.
Laboratory |
Analyses |
NorWest Labs
Winnipeg
(204) 982-8630 |
% moisture, Total N,P,K,Na,
E.C.
above plus S,pH,Ca,Mg,ammonium-N |
Enviro-Test Labs
Winnipeg
(204) 945-3705 |
Solid = Total N,P,K,S,%
moisture
Liquid = Total N,P,K,S,ammonium + nitrate-N |
AGVISE LABS
Northwood, ND
(701) 587-6010 |
% moisture, Total N,P,K
above plus S,Ca,Mg,Na,Mn,Cu,Fe,Zn |
Dairyland
Arcadia, Wisconsin
(608) 323-2123 |
% DM, Total N, P, K
above plus ammonium-N, above plus S |
Stratford Agri Analysis
Stratford, Ont
(519) 273-4411 |
% moisture, Total N,
ammonium-N,Ca,P,K,Mg,Na,Fe,Cu,Mn,Zn |
Agri-Food Labs
Guelph, Ont
(519) 837-1600 |
Liquid = Total and ammonium-N,
P,K,total salts
Solid = %DM,Total N,P,K |
Analytical Services
University of Guelph
(519) 824-4120 (2494) |
%DM, Total and ammonium-N,P,K |
Summary of Hog Manure Analysis
The agronomic value of manure can vary widely from place to
place, according to feed ration, management practices, storage facilities and weather
conditions. Data bases of information pertaining to the nutrient contents of manures are
currently being developed and expanded, such as in Table 1:
Table 1. 1996 Summary of Hog Manure Analysis -
Norwest Labs, Winnipeg |
|
TKN |
Ammonia |
Organic
Nitrogen |
P2O5 |
K2O |
Na |
EC |
Moisture |
|
----- |
----------- |
lb/1000 gal |
---- |
------ |
------ |
mS/cm |
% |
# samples |
90 |
78 |
78 |
89 |
89 |
89 |
89 |
89 |
high* |
30.7 |
21.9 |
8.8 |
23.5 |
17.3 |
5.1 |
16.1 |
97.9 |
average |
27.3 |
19.2 |
8.1 |
18.6 |
15.6 |
4.5 |
14.8 |
97.3 |
low* |
23.9 |
16.5 |
7.4 |
14.0 |
13.9 |
4.0 |
13.4 |
96.8 |
*Extreme values have been
disregarded. 9 times out of 10 the sampled values fall between the high and low values
listed above.
|
Treat livestock manure as a fertilizer. Once
its nutrient content is determined, manure can be managed to benefit crop production with
minimal risk to soil and groundwater contamination. The three key managmement points to
remember are:
- Soil Test
- Manure Analysis
- Adjust fertilizer rates accordingly
REFER TO FARM PRACTICES GUIDELINES FOR PRODUCERS
IN MANITOBA:
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