Page 158 - Nutrient Management Planning Guide

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Manure Sampling

Solid manure can also be collected during field

application. Send a minimum of three or more composite sub-samples for analysis per field, depending on the size of the area. Although messy, this method has the added benefit of being more accurate because any N lost through volatilization during surface application will not be included in the samples.

Sampling Solid Manure During Application

Divide the area to receive manure into sample 1.

collection zones according to the planned pattern of application. Place several (five to six) tarps in each zone such that they catch the manure from several spreader passes across the field (Figure 4.2.8). Manure collected on tarps in each zone of the application area serves as the basis for building composite-sub-samples for analysis.

Thoroughly mix the manure sampled from 2.

each tarp. Depending on the size of the tarp, take two to three samples using the shovel or pitchfork from each tarp and place them in the wheelbarrow. Avoid larger pieces or chunks of bedding.

If the amount of manure collected exceeds the 3.

capacity of the wheelbarrow, each time the wheelbarrow is two-thirds full, thoroughly mix the material and remove one or two shovelfulls to the pail or suitable mixing area.

Collect samples from all collection zones and 4.

take this material to the designated mixing area (tarp, plywood or concrete pad). Follow the method described in “Sampling Solid Manure During Application”, steps 3 to 9, to develop a composite sub-sample of solid manure.

Repeat steps 1 through 4 for all sample 5.

collection zones.

Figure 4.2.8 Tarp Placement for Collecting Solid Manure During Application

Sampling Stockpiled Manure

Stockpiles of solid manure, litter and compost are highly variable, so as a general rule, the more variable the stockpile of manure the more extensive the sampling strategy. Large, highly inconsistent piles require more extensive sampling compared to smaller, fresher or more consistent piles.

To get an accurate representation of most solid stockpiles, send away a minimum of three composite sub-samples based on samples taken from 10 to 15 points on the pile (i.e., three composite samples based on a total of 30 to 45 sampling points). If a portion of the pile is being applied, sample only that portion.

To obtain a representative sample from a solid manure storage facility, collect multiple sub-samples from throughout the pile when the nutrient content is fairly stable. Do not sample from freshly piled or turned manure unless it is going to be spread in the next few days.

Assemble the following equipment:

20 L (5 gal) plastic pail • wheelbarrow • shovel, pitchfork or solid manure-sampling probe •

(Figure 4.2.4) tarp, a piece of plywood or a concrete mixing area • one or more large plastic re-sealable freezer bags •

Nutrient content should stabilize within two weeks of creating a new pile or turning an existing pile.

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