Manure management decisions are complex. While these decisions are an intricate part of the dairy production system, manure management also involves a variety of subjects, several different segments of society and a broad range of agencies. That?s why we?ll explore how manure management differs from most other aspects of dairy farm management.

Unique Aspects of Manure Management

Manure management is quite different from most other farm management problems, mainly because problems related to manure are of a different type and more social in nature than experts in the physical sciences are accustomed to addressing. Some examples of manure management problems are:

Solutions require knowledge from several different subject matter areas; A wide variety of agencies and individuals - local, state and federal - have different perspectives on manure; This issue has the attention of several segments of society besides dairy, livestock and poultry producers and all of this attention isn’t necessarily an asset. This is particularly true in areas where animal agriculture is well established and wishes to coexist in harmony with other segments of society — some already there and some new to the area; and It is a cost of operation on the dairy farm. Usually, a positive return is anticipated as the result of making an on-farm capital investment.

Producers invest in manure storage systems for other than economic reasons because added profitability is not the incentive. These reasons include:

Convenience (i.e., reducing the need for daily hauling);To prevent discharge of pollutants to surface waters;Regulatory and legislative pressures; and To better utilize the nutrients contained in manure.

Selected manure treatment methods including the following, may improve finances:

Composting adds value to manure, resulting in a product that has potential market value; Reclaiming sand from sand-laden manure reduces complications with both handling and storing manure;Reusing the reclaimed sand for freestall bedding reduces the amount of new sand purchased; and Electricity generated from methane, a product of anaerobic digestion of manure, may be an additional revenue source.

Managing Manure Nutrients

Manure management must be part of the overall farm management plan. Decisions about manure system design are an integral aspect of the decision-making process when selecting facilities for the animals, as well as designing the cropping program.

Utilizing manure nutrients in the cropping program to offset the use of commercial fertilizers is not new. We know, for example, manure is a good source of phosphorus. In Michigan, estimates indicate manure produced by animals in the state can supply about 50 percent of the total phosphorus for crops grown in the state. But, while manure may indeed meet the plant?s requirements for one nutrient, the soil may already have sufficient quantities available of another, thus raising many concerns. Also in Michigan, estimates suggest that 50 percent of the soils already have phosphorus contents sufficiently high to warrant caution when applying manure. Therefore, if manure is applied to the land, that land must be determined deficient in meeting the nutrient needs of the crop grown in the case of those nutrients contained in the manure. Not applying nutrients in excess of a crop?s needs is in the best interest of both good nutrient management and responsible environmental management.

Producers should consider the following when managing manure nutrients:

If the land available for spreading manure already has more than enough of at least one of the nutrients needed by the crop, look to nearby crop farmers as an alternative;Buy additional land. Although it will be costly, it provides additional places to spread manure; Manure transportation costs must be weighed against the value of manure nutrients;Pumps may be used to move manure up to several miles to remote storage, or to apply it directly to the land;Consider irrigating. However, the odor created can be substantial. If sand is used for freestall bedding, special consideration must be given to remove the sand to minimize impact on pumping and irrigation equipment; and Maintaining a low profile for the dairy ? reducing visual awareness, reducing objectionable odors and avoiding runoff - is advised in all cases.

Manure Management Critical Decisions

Manure management decisions are related to the requirements of a well thought-out management program, including a clear description of the environment provided for every animal on the farm. Thus, all decisions regarding facilities and manure management must be made with a full awareness of the consequences.

Producers should consider the following for freestall bases and bedding:

Choice of bedding should reflect management style and goals for level of milk production and somatic cell count;Ensuring cows have six to eight inches of loose sand and rubber-filled mattresses with organic bedding on top are two methods for satisfying the freestall bed requirements promoting cow comfort and good udder health; and The only reasons for not using sand are the difficulty it may add to the manure system, or the availability of high quality sand. Ultimately, this may lead to a decision to use sand despite the difficulties, but seek ways to reduce its impact on the manure system, or use mattresses or organic bedding and avoid the problems with sand altogether.

Consider the following recommendations for freestall barns with or without exercise lots:

Cover all feeding, resting and traffic areas to reduce the amount of polluted runoff that must be controlled and handled through the manure storage and handling system; and While many farms have outside lots and traffic areas, keep the uncovered areas used by animals at a minimum. Also, clean runoff water should be diverted away from the manure storage area.

Manure System Design: Decision Priorities

While the traditional view of manure system planning centers on the handling system components ó collection, transfer, storage, possible treatment and nutrient utilization ?sound engineering design assures that all components will operate together economically and effectively to manage manure until it reaches its final destination.

Categorizing manure management decisions helps design a manure system to meet all the needs of a dairy. These categories should be considered in the planning process:

Decisions that consider the dairy farm in the broadest possible context are high priority and should be made early in the design process; Make decisions early in the process regarding the method of applying manure to the land and whether it will be handled as a semi-solid or liquid; and After choosing the type of bedding and establishing the method of land application, address those decisions involved with our traditional view of manure system planning. This involves collection of manure in the barn, transfer to storage, the type of storage and length of storage period involved. Manure management is an extremely complex issue and is different from other farm management problems. Therefore, planning for manure management must be an integral part of planning the overall farm system since investments in manure management systems cannot be justified on strictly an economic basis.

Source: Michigan State University
Author: William G. Bickert