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Manure Sampling

Important Terms

Table 4.2.1 Key Terms and Definitions

Term Definition

Dilution The process of making weaker or less concentrated, by the addition of water. Re-suspend

To mix or agitate a solution (liquid manure) so as to mix the solid material back into suspension. Spatial Variation

The variation in properties (i.e., nutrient content and manure consistency) laterally across the manure pile or storage, or vertically downward through the manure pile or storage. Stratification

The formation of layers of sediment and nutrients in a liquid manure storage. The various materials separated out because of differences in size and density. Temporal Variation

The variation in properties (i.e., nutrient content and manure consistency) that occurs with time in the manure pile or storage. Total Kjeldahl Nitrogen

This is the amount of total nitrogen contained in an organic material (i.e., manure or soil) as determined by the ‘Kjeldahl’ digestion method.

To determine an appropriate manure application rate, it is critical to know the nutrient content of manure. This will help meet crop requirements, maximize yields, minimize environmental impact and optimize economic benefit.

Manure Sampling Versus Book Values

Nutrient content of manure is determined from book values or lab analysis. Manure nutrient composition varies widely between farms due to a host of factors such as: differences in animal species, bedding and feeding practices and type of manure (solid or liquid). Book values may not reflect the nutrient composition of individual farms. Therefore, the only way to get reliable, farm specific estimates of manure nutrient content is by sampling and lab analysis (Table 4.2.2).

Table 4.2.2 Variability in Analysed Nutrient Content of Manures Compared with Book Values.

Manure Type Data Source Total Solids (%) Total N (%) Total P (%)

Dairy MWPS 1 (book value) 8.0 0.39 0.19

Source 1 6.7 0.31 0.11 Source 2 8.3 0.36 0.15 Source 3 10.3 0.50 0.21 Source 4 5.6 0.34 0.13 Swine MWPS (book value) 1.0 0.06 0.04

Samples 0.61 0.17 0.03 Poultry MWPS (book value) 75.0 2.35 2.40

Samples 66.5 3.02 2.69

1 Midwest Plan Service 1993

Adapted from Dou et al. (2001)

more info

The commonly used standard values for manure nutrient content in Alberta appear in the AOPA Manure Characteristics and Land Base Code published by AF. This publication can be obtained from the publications office of AF by calling toll free 1-800-292-5697 or searching Ropin’ the Web.