What is manure

Manure is a valuable source of nutrients for crops and can improve soil productivity. Manure properties depend on several factors: animal species; diet, digestibility, protein and fiber content; and animal age, housing, environment, and stage of production. Manure is characterized in several ways. Important properties for manure collection, storage, handling, and utilization include the solids content (the percent of solids per unit of liquid) and the size and makeup of manure solids (fixed and volatile solids, suspended solids, and dissolved solids). Nutrient content, primarily nitrogen, phosphorus, and potassium, is important as it affects land application rates and treatment techniques. Manure components can be characterized as organic and inorganic. To help control disease and parasites, human wastes should not be mixed with animal manures. Handling Characteristics The quantity, composition, and consistency of manure greatly influence livestock manure facility design. The handling characteristics of manure vary, depending primarily on the amount and type of solids present. The boundary between handling classifications is not fixed but varies with a specific composition. Manure can be classified, in general, based on how manure must be handled. Manure handling characteristics vary as consistency changes from liquid to solid. On one end of the spectrum is lagoon liquid with a very low solids content (less than 1%) that can be handled using conventional centrifugal pumps. Lagoon liquid can be irrigated using either big guns or center pivot irrigation systems with small nozzles. On the other end of the spectrum is solid manure that must be handled with front-end loaders and/or pitchforks. Solid manure normally has more than 20% solids. In between are the more difficult to handle manures, the ones containing from 5 to 20% solids. The moisture content of the manure is the main determining characteristic, although solids size and the presence of bedding also can influence the equipment needed for handling, treating, and transporting. Solids generally tend to settle, but very thick manures (more than 10% solids) hinder settling, and may result in more uniform manure than a settled, thinner one. Sand is another challenging solid that’s sometimes used as dairy bedding. Sand requires special settling and handling procedures due to its high density and abrasiveness. Nutrient values are related to solids concentrations. In general the higher the solids concentration, the higher the nutrient concentration. Estimates are available for most manure types, but to really know what manure contains, representative samples must be analyzed. Estimates and tabular values must be used with caution. They are useful for planning purposes, but once a facility is established, the best way to determine nutrient and handling characteristics is to obtain good representative samples and have them analyzed. Liquid Manure with up to 4% solids content can be handled as a liquid with irrigation equipment. Liquids that have had the larger solids removed or manure with dilution water added may contain 4% or fewer solids.