Livestock manure is a great source of plant nutrients and definitely has value as a fertilizer. But, determining a fair price to pay (or charge) for livestock manure can be a complex task because of the number of variables involved. That being said, here are a few factors to consider when determining the value of manure.
The level of each nutrient supplied by manure can be accurately assessed with a manure test. The results of a current manure test are a vital first step in predicting the value of manure since nutrient content can vary greatly from one farm to the next. Factors such as the type of animal producing the manure, the type of feed and feed supplements, bedding type and amount, manure collection and storage facilities, water content, and many other factors will affect the nutrient levels in manure. Once the test results have been obtained, the “gross value” can be calculated based on current commercial fertilizer prices.
When purchasing manure, crop producers should only assign value to the nutrients that they would have applied with commercial fertilizer. So, if a crop producer would normally have applied fertilizer at the rate of 140-70-100, but a given quantity of manure per acre would yield a test of 140-80-140 for example, that producer should not place a value on nutrients in the manure that would significantly exceed the levels he or she would normally have applied. Some would argue that these nutrients can be “banked” in the soil, which can be true in some cases and in small amounts. But as a general rule, an adjusted gross value should be used based on the actual crop needs.
Once the adjusted gross value of the manure has been figured, mileage and application costs must be accounted for. Mileage fees and the cost of application will be much greater when applying manure than commercial fertilizer. These additional costs should be subtracted from the gross value on a per acre basis. The gross value per acre, minus all trucking and application charges, would result in the net value of the manure.
Finally, there are other factors-both positive and negative-that should be considered. Soil compaction and/or tire tracks left by the equipment can be an issue in certain situations. Also, the high water content of some manure sources can require a large amount of liquid to provide the necessary nutrients. This can be positive or negative, depending on field conditions and soil moisture.
The negative factors are usually outweighed by the many positive factors associated with manure. Manure provides readily available nutrients as well as nutrients that will be released over the next 2-3 years. Manure also affects the mix of micro organisms in the soil, increases the biological activity, increases organic matter, and improves soil structure. While these factors are hard to assign dollar values to, they should definitely be considered when determining manure’s true value.