OTTAWA - Americans love their meat. So much so, in fact, that Americans consume two to three times as much meat as in developing nations and as much as 60 percent more than in other developed nations, such as Spain and Australia.
To keep up with this demand, livestock farmers have long since taken a cue from other industries and grown in size. Concentrated animal feeding operations (CAFOs) are common and maintain thousands of animals at a single site. And where there are that many animals, there is a commensurate amount of manure.
Thankfully, manure is rife with the nutrients necessary for the growth of a host of plants, including the grasses and grains that serve as feed for the animals that produce the manure that serves as fertilizer to produce the grass and grains that serve as feed. The cycle is never-ending and remarkable in its complex simplicity. There are, however, drawbacks.
CAFOs in Northwest Ohio use a relatively inexpensive resource to help manage the sheer volume of manure produced at their facilities: water. In short, they hose down the areas where the animals excrete and sluice the resultant slurry into holding areas. While a relatively inexpensive means of keeping livestock areas clean, water significantly increases the volume of manure, creating more immediate supply than there is a demand for, more than there is available cropland in need of fertilization.
The liquid nature of the fertilizer creates even greater problems in that it is fluid and therefore less likely to remain fixed in place. And herein lays the greatest risk to area waterways. For what promotes the growth of crops in fields is equally successful in promoting the growth of algae in streams, rivers and lakes.
Over the past decade, significant increases of harmful algal blooms (HABs) have posed a significant problem. Of particular concern is what is commonly referred to as blue-green algae. Blue-green algae, also known as cyanobacteria, are microscopic organisms found naturally in surface water that can sometimes overproduce to form HABs. HABs can potentially produce toxins capable of causing illness or irritation, sometimes even death, in pets, livestock, and humans. In addition to producing toxins, blue-green algae can also pose other treatment challenges for public water OVERSET FOLLOWS:systems including taste and odor issues. Most dramatically affected by HABS in recent years are Grand Lake St. Marys and Lake Erie, both of which have seen significant increases in the presence of blue-green algae to the point where recreation and tourism on both bodies have been curtailed and even quarantined. And these same issues are occurring in other states, as well. Lakes and rivers in Wisconsin, Indiana, Illinois, Michigan and Maryland, as well as the Mississippi River and the Gulf of Mexico, have all been subject to HABs.
"Agricultural runoff is one of the single greatest contributors to algal bloom," said Dr. Robert Midden, a professor at Bowling Green State University, whose oversight includes the study of a process the nature of which is to, hopefully, reduce run-off. "What were working on is a potential solution to a major challenge, which is how to best use the manure from the CAFO in Ohio as a fertilizer. It's aimed at addressing one of the most significant contributors to algal bloom: manure."
The study, a joint effort of the Village of Ottawa, the Putnam County Educational Service Center and Bowling Green State University, proposes the removal of most of the moisture from the manure produced at CAFOs, thereby creating a material that is easier to transport and more stable when applied as fertilizer to cropland. In addition, through the introduction of a naturally occurring polymer, the nutrients within the manure, such as phosphorous, a principal agent in the promotion of HABs, are bound to the material's inert components and, ideally, slowly released over time.
"The process that we're trying to develop includes a material that holds onto nutrients which are then released slowly so that the plants can absorb them," Midden explained. "If you release the nutrients at the right rate, the plants will absorb most of them and there are fewer then to discharge from the fields."
While the study has produced some positive results in the laboratory, as well as in one large event outside the lab, Midden acknowledges that it still remains in its early stages.
Midden expressed the belief that, by spring of 2014, larger experiments utilizing greater volumes of liquid manure from multiple sites and applied to various soil types will prove possible and bring with them new insights.
story created on Monday 9/30/2013 at 7:38:48 pm by Anne Coburn-Griffis
story modified on Tuesday 10/1/2013 at 4:54:48 pm by Kirk Dougal