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Estimating Manure Inventory

Important Terms

Table 4.1.1 Key Terms and Definitions

Term Definition

Agitation The stirring up or mixing, in this context, liquid manure in a storage facility. Circumference The outer boundary of a circular area.

Cosine

The ratio of the length of the side adjacent to an acute angle of a right triangle to the length of the hypotenuse. Abbreviation: cos. Diameter

A straight line passing through the center of a circle or sphere and meeting the circumference or surface at each end.

Freeboard The distance from the top of the manure storage to the top of the manure. Hypotenuse The side of a right triangle opposite the right angle. Perpendicular Meeting a given line or surface at a right angle.

Pi (π)

The mathematical constant π is a transcendental real number, approximately equal to 3.14159, which is the ratio of a circle’s circumference to its diameter. Radius

A straight line extending from the center of a circle or sphere to the circumference or surface, respectively. The radius of a circle is half the diameter. Right Angle An angle that measures 90 degrees.

Windrow A row or line of any material, but in this publication it refers to stored manure.

The weight or volume of available manure should be determined prior to land application. There are at least three reasons why getting an accurate estimate of manure volume or weight is important:

The weight of available manure, together with •

nutrient content, can be used to estimate the required land base for manure utilization. To determine if a producer is subject to additional •

requirements under AOPA (e.g., if more than 500 tonnes of manure is handled). To estimate the time required to apply manure. •

Weighing manure is the most accurate method for determining the quantity of manure applied. Physically weighing manure may not be practical or safe, in which case manure inventory must be estimated. There are three options for estimating manure inventory:

Standard estimates or “book values” for average •

manure production for different livestock. Historical manure application records, or capacity •

indicators in storage facilities. Calculated estimates of pile weight or volume •

contained in a storage facility.

Standard estimates or “book values” are useful when estimating storage needs, but are of limited value for nutrient management planning. Standard values may not reflect the actual volume or weight of manure produced because of factors such as precipitation, feeding and bedding practices and water conservation practices.

Operations may have manure application records documenting the volume of manure applied in the past (e.g., number of loads hauled). Provided the operation has not changed in size, management or type of livestock this estimate can be reliable enough for nutrient management