Slurry Manure Collection and Handling Systems

Slurry manure is typically generated in systems where little or no bedding is added to the excreted manure/urine. Slurry manure is typically between 5% and 15% solids. It is “thicker” than liquid manure, but cannot be stacked or handled the same way as solid manure. Some common system for handling and storage of slurry manure are described in this article.

Collecting Slurry Manure

Slotted Floor

The simplest manure collection arrangement for slurry manure is the slotted or perforated floor over a manure collection tank. In this scenario excreted manure simply falls through openings in the floor on which the animals stand and collects in a tank below.

Slotted floors above a manure tank are a simple means of collecting slurry manure.

Scrapers

Slurry manure can also be collected using scrapers. In this case the manure is usually confined in an alley (dairy freestall barn) or gutter under slats (swine confinement building). A scraper moves along the length of the alley or gutter and deposits the slurry manure in a reception pit or tank at the end.

Mechanical or tractor-mounted tire scrapers can be used to collect slurry manure in a dairy freestall barn.

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Vacuum

Another type of slurry manure collection device utilizes a vacuum to “suck” slurry manure from a concrete surface and deposit it into a tank. This approach eliminates the need to pump the slurry manure into a tank or wagon.

Labor is reduced when a suction or vacuum is used to collect slurry manure from a concrete alley.

Slurry Pumps

Slurry manure has fluid properties that allow it to be moved by pumps that are specially designed to handle thick fluids containing solids and stringy material. Slurry manure pumps are designed with open-type impellers and usually have cutting or chopping devices at the inlet to the impeller to minimize plugging problems. Low-pressure/high volume slurry pumps are used to fill tankwagons and move manure in other applications where higher pressures are not required. High-pressure slurry pumps are used to move manure through long pipelines and provide the needed pressure for land application in crop fields.

Slurry pumps have open impellers and cutter/chopper blades designed to handle manure with high solids content.

Low-pressure/high volume slurry manure pumps are used to quickly fill manure tankwagons.

High pressure slurry manure pumps can move manure long distances through pipelines to field application equipment.

Transporting Slurry Manure

Tankwagons

Tankwagons can be used to transport or move slurry manure from one point to another, usually from a manure storage facility to a crop field. Tankwagons are available in a variety of sizes from small (1,000 gallons) to quite large (12,000 gallons). Tankwagons typically serve the dual function of transporting slurry manure to a crop field and spreading or injecting the manure into the soil for crop nutrient uptake.

Large tankwagons allow producers to empty manure storage facilities quickly with less labor.

Pipelines

Since slurry manure has fluid properties it can be pumped through pipelines from storage to crop field as an alternative to hauling with a tankwagon. Pumping is a “continuous flow” process whereas hauling is necessarily a “batch” process. Hence pumping can offer significant advantages over hauling in moving large amounts of manure in shorter lengths of time. Tankwagons are generally used to move manure over longer distances although pipelines have been used for distances up to five miles.

Rigid aluminum irrigation pipe has been used for pumping slurry manure in the past. However the labor advantages of using flexible “layflat” tubing for pumping make this type of pipeline more attractive in many cases. Long lengths of this tubing can be stored on reels and placed overland with much less labor than is required with rigid tubing.

Flexible hose or tubing requires less labor for a manure pipeline than rigid pipe.

Slurry Manure Land Application

Field or land application of slurry manure requires that the application devices place the manure in the proper location and at the proper rate for good nutrient management practices. Devices which inject or incorporate manure into the soil are generally preferred since the following advantages are associated with this practice.

  1. Odor is reduced
  2. More nutrients are retained
  3. Runoff potential is reduced

Injection units place manure into the soil to reduce odor, conserve nutrients and minimize runoff.

Some injection units are designed for sod with minimal surface disturbance.

Authors: Charles Fulhage and Joe Harner

Photos: CC 2.5 Charles Fulhage or Joe Harner