Author
 |
Owens, Lloyd |
|
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 8/21/2003 Publication Date: 10/23/2003 Citation: OWENS, L.B. REDUCTION OF NITRATE LEACHING IN PASTURES - GRAZING VS HAYING. ASA-CSSA-SSSA ANNUAL MEETING ABSTRACTS. 2003. CD-ROM. MADISON, WI. 11-Owens984780-poster. Interpretive Summary: Technical Abstract: In some high fertility, high stocking density grazing systems, nitrate (NO3) leaching can be great, and groundwater NO3-N concentrations can exceed maximum contaminant levels (MCLs). Two management practices were studied with regard to reducing NO3-N concentrations in groundwater following a fertilized, rotational grazing management practice from which groundwater NO3-N concentrations exceeded MCLs. Using four small watersheds (each approximately 1 ha), rotational grazing of a grass forage without N fertilizer being applied and removal of unfertilized grass forage as hay were the alternative management practices used. Groundwater was sampled at spring developments, which drained the watershed areas, over a 7 year period. Peak groundwater NO3-N concentrations prior to the 7-yr study period ranged from 13 to 25.5 mg/L. Groundwater NO3-N concentrations progressively decreased under each watershed and both management practices. Following 5 years of the alternative management practices, groundwater NO3-N concentrations ranged from 2.1 to 3.9 mg/L. Both grazing and haying, without N fertilizer being applied to the forage, were similarly effective in reducing the NO3-N levels in groundwater. Thus, when fertilizer N is omitted, both haying and grazing can be effective in reducing high NO3-N concentrations in groundwater. |
