A dirty job but someone gets to do it: Grassland lab receives $400,000 grant to study biosolid fertilizer

biosolid fertilizer

Trent Cook empties treated waste into the Maximizer, the machine on the left that looks somewhat like a trash bin on wheels, that separates solid from liquid waste. The waste is then sprayed onto nearby hay fields as fertilizer.
–photo by Mitch Green/Telegram

By Fred Afflerbach- Published September 17, 2008

Two members of a local research group aren’t afraid of getting their hands dirty. Or a little smelly.

Scientists from the Grassland, Soil and Water Research Laboratory in Temple are taking a close look at how the environment could be affected by using biosolids for fertilizer in agriculture.

The research is possible because of a $400,000 grant recently awarded by the U.S. Department of Agriculture.

The two scientists, Dr. Mari-Vaughn Johnson and Dr. Virginia L. Jin, will take back to their laboratory soil samples from two Central Texas locations where for years biosolids have been applied to hay fields.

“For thousands of years we’ve been using them (biosolids) to grow crops with. The point of this research is to better understand. So we can use it responsibly,” Dr. Johnson said. “It makes people a little squeamish and a little uncomfortable to talk about it, but it’s something – as our population continues to grow – we’re really going to have to figure out what to do with it.”

The scientists are focusing on a group of chemicals called endocrine disrupting compounds that are often found in human waste, and how they could affect plants, animals and humans after significant rainfall. In the lab, they will use adjustable showerheads to manipulate weather conditions.

These chemicals begin innocently in human waste.

“Every time you take aspirin, your body uses what it can, and it expels the rest. Vitamins, birth control, all of it,” said Dr. Johnson. “You are getting rid of that and it is going into these biosolids and it’s being land applied and right now there’s not a management protocol for pharmaceuticals in waste.”

Working with a local rancher and the city of Austin, the researchers will extract soil samples from several different pastures.

“We’ll actually bring back cores, probably a foot in diameter. We’ll jam a PVC pipe into the ground and dig it out so that core of solid is undisturbed in the center. It’s intact. It’s much more realistic to do it that way,” Dr. Jin said.

The researchers plan to extract some of these samples from the Grandy Ranch, a sprawling patchwork of green fields in western Bell County near Nolanville.

Over the course of three decades, Glen Grandy has slowly turned several hundred acres of hard scrabble into pastures thick with coastal bermuda. The grass keeps 150 cattle fed and provides income through hay sales. Grandy forgoes the popular commercial fertilizers that are sold by the ton and measured by their mineral composition. He applies biosolids from septic tanks and municipal waste plants.

Grandy said he is happy to provide the researchers with access to his ranch. Although he already submits to mandatory state testing, he said this is a good idea.

“That’s not something that we test for, but we should be concerned about,” Grandy said, regarding the possibility of pharmaceuticals leaching into the soil. “And the USDA’s testing process is to find out is this something we should be concerned about. I’m very much interested in that too, because I want to be a good steward of the land. We’re not out here as a dump site, we’re a beneficial site.”

The researchers also are working in Austin at the Hornsby Bend Biosolids Management Plant. The plant basically applies the same methods as Grandy, but on a larger scale – 1,200 acres.
The research will last about 2½ years. Depending on funding, it could continue longer.

–Reprinted with permission of the Temple Daily Telegram

Comments are closed.