Hog farm recovers 90% of its phosphorus from manure

The hog industry’s first full-scale dedicated phosphorus (P) recovery system has been commissioned at Storms Farm in Bladenboro, N.C., capturing 90% of the farm’s total phosphorus from all the hog waste generated daily. According to farm owner William Storms, “It’s working well!…I can take excess phosphorus off the farm now and put it where I want it. I’d say everyone should look at doing this.”

The high P recovery percentage is made possible by Storms’ initial installation of a custom-engineered anaerobic digester by Wisconsin-based DVO, Inc. Doug VanOrnum, DVO’s VP of Strategy & Technology, says, “Complete digestion of all the farm’s waste is a critical first step to the phos recovery unit’s performance. Covered lagoons and other older treatment methods could never process Ag wastes nearly as efficiently or as thoroughly as is necessary for us to achieve this level of performance."

Many people do not realize that phosphorus – necessary for life as without it crops cannot grow – is not a renewable resource. Scientists say global supplies are already starting to run out. However, we also know that too much of it in one place can be harmful to the environment.

At the Storms Farm digester nothing is separated beforehand, 100% of their manure goes in. The digester does not destroy any nutrients such as N, P & K either. Instead, it transforms them into "plant-ready" fertilizers that crops can use right away. Furthermore, properties that are unique to the DVO digester also allow for follow-on nutrient recovery steps like this to be economical too.
 
Says VanOrnum, “In this example, capturing 90% of the farm’s phosphorus costs less than half a cent per hog, per day. Some nitrogen and essential micro-nutrients are also captured. These combined fertilizers are collected in a condensed, stackable solid product that are deposited via conveyor directly into truck bed or trailer for easy transport.”
 
According to Storms, “Some of my neighbors are already requesting this product for their own use.”
 
The P-rich solids have an earthy smell like peat moss. “In fact, it’s an excellent peat moss substitute,” says VanOrnum, referring to yet another non-renewable & dwindling resource. 
 
This level of farm waste treatment addresses head-on many of the challenges that the hog industry has faced for decades. With it, animal operations nationwide can safely and economically redistribute their nutrient fertilizers to where they are really needed. Including, off their property entirely, and/or away from sensitive watersheds areas.
 
Storms Farm also sees added benefits to having this capability: The pollution potential of the remaining treated wastes are significantly reduced. Odor from waste storage and handling, and harmful pathogens such as e-coli, are virtually eliminated. Greenhouse gas impacts from long-term waste storage are greatly reduced too. Even lagoon storage requirements are a small fraction of what they were previously.
 
“Farmers who perform this level of advanced nutrient management on their wastes are not only making good business sense – they are better community neighbors too,” says VanOrnum.

Various methods have long existed to treat animal wastes. Unfortunately, in too many instances those earlier practices either weren’t financially feasible, and/or the technology wasn't sufficiently robust, to make practical sense. Over time and with new advances that situation has changed significantly. Now, according to Storms Farm and DVO, both the farmer and their surrounding community can enjoy these benefits because, "It’s finally become practical to do so. A true win-win scenario that can also provide added revenues for the owner,” says VanOrnum.

Learn more about DVO's Phosphorus Recovery (PR) system here.