Studies show biosolids can boost soil phosphorus levels for years

Jan 23, 2013 by Ann Perry
Studies show biosolids can boost soil phosphorus levels for years
Agronomist Eton Codling inspects wheat plants grown in biosolid-amended soils. Yields from some biosolid amendments were higher, but yields from lime-treated biosolids were severely reduced. The unhealthy plant on the left is growing in soil amended with lime-treated biosolids. Credit: Stephen Ausmus.

Treated wastewater solids called biosolids are sometimes used by farmers to boost soil nutrient levels. Now research by a U.S. Department of Agriculture (USDA) scientist provides new information about how long those plant nutrients remain after biosolids have been applied to the soil.

This work was conducted by Agricultural Research Service (ARS) agronomist Eton Codling, and supports the USDA priority of promoting international food security. ARS is USDA's chief intramural scientific research agency.

Biosolids used in agricultural production have been processed to kill pathogens, and their use is strictly regulated to ensure that the materials don't harm the environment, human health or animal health. Farmers who follow pre- and post-application management regulations can obtain permits to apply biosolids to fields where food and feed crops are grown.

Codling measured mineral levels in three different soils that had received a single amendment from a biosolid processed either via high heat, additions of lime, , or air drying. The amendments, which were applied at several different rates to the soils, had taken place from 16 to 24 years earlier during previous studies on biosolids. As part of the earlier work, the fields had been cropped after the biosolids had been added, so the biosolid nutrients in the experimental fields had been available for crop uptake for at least 16 years before Codling began his research.

Codling observed that phosphorus levels were generally higher in the biosolid-amended soils than in soils that didn't receive the amendments. This strongly indicated that soluble in biosolid-amended soils could exceed typical plant requirements for years after biosolids were added.

Codling, who works at the ARS Environmental Management and Laboratory in Beltsville, Md., also noted that phosphorus solubility varied with the biosolid type and application level.

Explore further: TransCanada seeks approvals for pipeline to Atlantic

More information: Read more about this research in the January 2013 issue of Agricultural Research magazine.

add to favorites email to friend print save as pdf

Related Stories

Tracking triclosan's field footprint

Sep 10, 2010

A study by U.S. Department of Agriculture (USDA) scientists and cooperators provides new details about how fertilizing soils with biosolids also introduces triclosan -- an antibacterial agent in soaps and other cleaning supplies ...

Biosolids microbes pose manageable risk to workers

Oct 27, 2008

Class B biosolids are sewage sludges that have been treated to contain fewer than 2.0 x 106 fecal coliforms/dry gram. The USEPA estimates that 6.3 million tonnes of Class B biosolids are generated in the United States each ...

Wastewater treatment lowers pathogen levels

Jan 03, 2011

A recent study by a team of researchers at the University of Arizona has tracked the incident of pathogens in biosolids over a 19 year period in one major U.S. city. In the same study, the researchers also analyzed pathogen ...

Recommended for you

Bladderwrack: Tougher than suspected

4 hours ago

The bladderwrack Fucus vesiculosus is actually one of the most important species of brown algae along the North Atlantic coasts. But for years their populations in the Baltic Sea were declining. Looking for the reasons, biolog ...

Australia set to pay polluters to cut emissions

15 hours ago

Australia is set to approve measures giving polluters financial incentives to reduce emissions blamed for climate change, in a move critics described as ineffective environmental policy.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.