re of 11-52-0 annually.
Bopp has experienced similar results on 145 acres of irrigated land, where he had biosolids applied from the Fremont wastewater facility. “I haven't used any (commercial) P since,” he says.
Corn and beans have yielded as well or better than other fields fertilized regularly with commercial fertilizer applied according to soil tests, Bopp says. Biosolids not only cut his fertilizer bill, they improved soil tilth, he adds.
He calls it a “huge savings,” but adds, “The only problem is, there aren't going to be enough (biosolids) to go around.”
The material, Class B, from the Fremont plant is about like potting soil, according to Schultz. It spreads evenly. You don't get the clumps that can occur with livestock manure spread on fields, he says.
Bopp disked in the biosolids he received, which were applied in the fall, and then incorporated further with field cultivation in the spring. Clausen says he incorporated biosolids on some acres and not on other acres, with comparable yield results between the two.
“Environmentally, it's a grand way to get rid of a product from these (municipal wastewater treatment) plants,” Bopp says. And economically, the more fertilizer prices rise, the farther you can transport it for its fertilizer value, he adds.
Clausen and Bopp are among a group of Nebraska farmers who are comparing biosolids processed from municipal sewage sludge for crop production. They participate with the Nebraska Soybean and Feed Grains Profitability Project, an on-farm research program.
Biosolid substitution for commercial fertilizer is just one of many different practices farmers are researching for themselves on their farms. They receive guidance on setting up accurate comparisons from University of Nebraska Extension personnel. (You can review past results at http://farmresearch.unl.edu by searching biosolids.)
University of Nebraska Extension Educator Dave Varner in Dodge County, NE — where Clausen and Bopp farm — says farmers receiving biosolids from the Fremont plant have generally enjoyed successes similar to those that Clausen and Bopp have experienced. Many farmers trying biosolids have posted yields equal to or better than yields from crops where nutrient needs were met with commercial fertilizer. There's a long waiting list of farmers who want their turn at receiving this material, he adds.
Qualifying to receive it requires meeting certain federal, state and local environmental requirements, such as frequency of application, distances from streams and wells, slopes and application rates.
A little more than 7 million dry tons of biosolids were used or disposed of in 50 states in 2004, according to EPA. The 3,300 largest U.S. facilities generated more than 92% of the wastewater solids in the U.S., according to that survey. About 55% (3.9 million dry tons) of biosolids from those plants were applied to soils for various agronomic purposes (row crops, forestry, land restoration, etc.), according to EPA. Even so, the EPA estimates biosolids are applied to only 0.1% of U.S. agricultural land currently under cultivation each year.
Farmers like Clausen and Bopp applied biosolids at rates based on crop N needs. But, because of the composted material's higher P content, application rates are now based on crop P needs. In Nebraska, they are applied subject to limitations similar to those in effect for livestock waste applications, says Varner. He coordinates the biosolids program between farmers and the Fremont treatment plant.
That plant provides Class A biosolids. Using estimated commercial fertilizer prices, he calculates that a typical 10-ton/acre application of composted biosolids might be worth more than $500 of crop nutrients over a five-year period. The material is about 30% moisture.
Not all municipal wastewater biosolids are Class A. Class B can range from a liquid (2-5% solids) to dried products (80% solids), according to EPA.
CLASS B BIOSOLIDS are also processed to reduce pathogens, and can be safely applied to agricultural land, according to Varner. But, they are subject to greater ap