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Texas Agriculture Archive

September 20, 2002

Earthworms consume a combination of poultry litter and paper pulp waste to produce the valuable organic fertilizer—worm castings.

By Gene Hall
Publisher

If it comes out of a chicken, it's a problem. If it comes out of a big box full of worms, it becomes much more desirable, even valuable. The substance in question is manure. As the dairy farmers in Erath County and many poultry producers in various Texas locations know too well, disposal of phosphorus-laden manure has become a giant headache.

High levels of phosphorus in manure can cause abnormal nutrient levels in water, promoting aggressive growth of algae, a problem for water quality and treatment.

As a result, the ancient practice of using manure as a fertilizer, spread on fields of forages or crops, has been severely curtailed in many parts of Texas. This is the case in Camp County, one of Texas' top poultry producers. As you might expect, getting rid of the manure has become as big a problem there as it has elsewhere.

Into this somewhat unsettled situation, comes Jerry Guinn. Guinn is a longtime rancher in Camp County, but the product he's excited about these days is not beef. He is a compost producer now, and he says he is just beginning to tap into a very valuable market.

Jerry Guinn has discovered that red crawlers, the same earthworm that is so prized as fish bait, just love poultry manure, or litter, as it is commonly called in the industry.

"We sell worm castings, which is a nice name for worm poop," Guinn says. "The casting market is big and there's not enough castings in the area to furnish what needs to be available."

In fact, Guinn is encouraging others to get in the "litter-to-worms-to-compost" business. The market is vast, and Guinn says having more suppliers would help develop it for the benefit of all.

Jay Mertz, of Rabbit Hill Farm, is buying every pound of worm castings that Guinn can produce.

"It's black gold," Mertz says. "Animal agriculture is having more and more problems with animal waste, and this is a big part of the answer."

The process works like this. A producer, like Jerry Guinn, acquires the poultry litter and runs is through a drum digester, a device that dries the manure into a compost product. The product of that aerobic digestion is then placed in large box crates, with worms, and overlaid with a pulp paper waste product, also readily available in East Texas. For approximately 45 days, the worms munch their way through the litter and pulp waste, leaving the highly prized worm castings behind.

What goes on in those worm boxes is a physical and chemical process, incorporating naturally occurring microorganisms that transform a foul smelling and undesirable substance into an odorless and valuable product.

After 45 days, the material is screened, removing the worms, and sold to Mertz, who combines it with rabbit manure to produce a complete line of organic fertilizer. Worm castings have none of the offending odor of poultry litter. It smells mostly like nutrient rich black earth.

One of the advantages of producing this material is that it has value beyond the immediate area where phosphorus-laden soils have become a problem. Therefore, it can be removed from the watershed, and sold to satisfy a growing demand for organic fertilizer in Texas, the nation and even in international markets.

Guinn buys poultry litter, feeds it to the worms and sells the castings for $300 a ton. He hopes to expand, and at the same time, recruit more worm farmers.

Some worms, which are pure protein, are being used to develop animal feed. The worms can also be sold for the classic use, fish bait. But for Guinn, the critters are much more valuable as tiny little organic fertilizer factories. He sells some worms, but keeps most of them to produce castings.

Mertz says his biggest need right now is more worm farmers.

"From lines of animal feed, to organic fertilizers, we don't really know where it's going to stop," Mertz says. "In Texas, it's just in its infancy."

Conventional agricultural producers often view their organic counterparts with some degree of suspicion. The debate continues as to which production method is better, but in this case, it's irrelevant. Mertz admits that the cost of organic production is too high for use in much of conventional agriculture, but research continues.

In Camp County, Texas, however, the conventional and the organic have come together to begin the process of solving one of animal agriculture's most pressing problems.