EFFECTS OF BIOSOLIDS LOADING RATE ON NITRATE LEACHING POTENTIALS IN SAND AND GRAVEL MINE RECLAMATION IN VIRGINIA
The USEPA 503 biosolids utilization rules recognized the need for higher than agronomic rate applications to mined lands under the assumption that NO3-N contamination of ground-water will not be significant. We evaluated a range of biosolids loading rates (1x to 7x agronomic rate of 14 Mg/ha) with and without added sawdust (to adjust the applied C:N ratio to approximately 20:1) on a reclaimed gravel mined soil and an undisturbed prime farmland soil for three growing seasons. The two experimental blocks were cropped to corn (Zea mays) in 1996, and winter wheat (Triticum aestivum) and soybeans (Glycine max) in 1997. Root zone leachates were collected from zero-tension lysimeters under adjacent identically treated micro-plots. Effects of biosolids loading rate on crop yields were not as pronounced as expected due to relatively wet weather. Leachate NO3-N over the winter of 96/97 increased incrementally (from < 20 to > 100 mg/L) with loading rate (1x to 7x) and then declined sharply in March and April of 1997, finally approaching control level concentrations through the winter of 1997/1998 and beyond. Addition of sawdust significantly decreased NO3-N leachate levels at all biosolids loading rates except the 5x biosolids + sawdust treatment which exhibited a first winter spike in excess of 100 mg/L. Mass leaching losses of NO3-N ranged from 6 to 60 kg/ha, which was from 0.7 to 3.1% of total-N applied. These data indicate that higher than agronomic loading rates of biosolids do lead to enhanced NO3-N leaching potentials over the first winter following application. However, this “one-time event” supports the original USEPA presumption that some net leaching under elevated loading rates is to be expected, but it is a short-term, low magnitude effect.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
Document Type: Research Article
Publication date: 2003-01-01
More about this publication?
- Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed. A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.
WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
- Subscribe to this Title
- Membership Information
- About WEF Proceedings
- WEFTEC Conference Information
- Learn about the many other WEF member benefits and join today
- Ingenta Connect is not responsible for the content or availability of external websites