Manure value at historic levels

Jan 9, 2009
by WLJ
Manure value at historic levels

Manure from livestock producers, both large and small, has historically been viewed as a liability because of time needed to scrape, load, haul and spread. However, this is no longer the case. In fact, with the dramatic shift in fertilizer prices for nitrogen and phosphorus, the value of manure has never been higher and more economical to use as fertilizer. With overall input costs soaring, livestock producers will be ahead to utilize their manure effectively in their cropping operations and/or merchandise the manure as a potenti al revenue stream.

Feedlot manure will generally contain between 10 to 20 pounds per ton of both nitrogen and phosphate (P2O5). The nutrient profile can be influenced by many factors, including dietary nutrient levels, frequency of manure scraping, and length of stockpiling before spreading. As the diet fed increases in nutrient content above the animal’s requirement, the excess is simply excreted.

There are circumstances where it is more economical to feed excessive levels of nutrients. One instance is the use of byproducts, where increasing their use lowers cost per pound of gain. This also leads to overfeeding nutrients and increasing the levels of nutrient excretion. When lots are cleaned frequently, the nitrogen on the pen surface is captured at a higher rate. Since some nitrogen is volatile in manure, the longer it stays on the pen surface, the larger losses of nitrogen one can expect. Typically, 50 percent of the nitrogen excreted is lost to volatilization before it is scraped and land applied.

Also, for operations that scrape and stockpile manure for spreading at a later time, the nitrogen in the stockpiles will begin to break down over several months of storage. This is due to a compost-type effect where microbes use the nitrogen as an energy source.

However, since P2O5 is not volatile or reduced by composting, its levels are generally unchanged compared to the amount that is actually excreted. To obtain maximum fertilizer value of manure, proper nutrient crediting and timing of application and incorporation is needed.

While all of this may seem complicated to those thinking about utilizing manure, in fact they are all very manageable. When relating to these issues, once again the nitrogen portion of manure is the most sensitive. Nitrogen in manure is in two forms, inorganic and organic. In the case of scraped beef feed lot manure, about 35 percent is in inorganic form while 65 percent is in an organic form. The inorganic portion, otherwise known as ammonium nitrogen, is readily available for crop use. This is also the type of nitrogen that is volatile and lost from the pen or field surface.

Second, manure contains organic nitrogen which needs to undergo mineralization to be available for crop use. Typically, 25 percent of the organic nitrogen will mineralize for the next crop utilization, with 12 percent mineralized for year two and 6 percent for year three.

Thus, producers need to be aware of the nitrogen crediting that they can do to reduce cost on future years to fully utilize the nitrogen in manure that is applied. Finally, when solid manure is field applied, the impact of crop available nitrogen is directly related to the timing of incorporation into the soil. If manure is incorporated within one day of spreading, approximately 90 percent of the inorganic nitrogen will be retained.

However, if incorporation does not occur for seven days or longer, or in the case of no-till is solely surface applied, only about 5 percent will remain for crop use. In the case of phosphate, all will be retained for use regardless of application timing and incorporation.

Also, it is generally viewed that 100 percent of the phosphate in manure is available for crop use. Producers need to properly distribute nutrients to avoid a build up of an excessive amount of phosphate.

Historically, most producers have spread solid manure to meet the nitrogen requirement for the upcoming crop, but this also spreads enough phosphate for multiple years.

With many operations now implementing nutrient management plans, the basis of application is on a phosphate removal rate based on crops planted.

While hauling manure longer distances was not previously economically justifiable in many cases, producers need to reevaluate their nutrient distribution based on current fertilizer prices.

Given current fertilizer costs of $0.90 per pound of nitrogen and $1.25 per pound of phosphate, the value of manure is at historic levels. With an estimated 15 pounds of nitrogen per ton in feedlot manure, the value would be estimated to be $13.50 per ton. However, each producer must evaluate the true value of nitrogen based on potential nitrogen losses as described earlier. For phosphate, considering an average amount of 15 pounds per ton of feedlot manure, the value would be $18.75 per ton. Thus, in a 15-ton box spreader of manure, the phosphate contribution would be about $280, without considering the nitrogen value. Only three years ago, this same amount of phosphate was worth $60 to $70 per 15-ton load. Not only can livestock producers save on fertilizer input costs, selling manure to neighboring crop producers can be a revenue stream.

The price that can be negotiated is situation specific and needs to be workable for both parties. — Kansas State University Ag Extension