
Agricultural and Biosystems Engineering Publications
Document Type
Article
Publication Date
11-2010
Journal or Book Title
Journal of Environmental Quality
Volume
39
Issue
6
First Page
2006
Last Page
2015
DOI
10.2134/jeq2010.0151
Abstract
Many croplands planted to perennial grasses under the Conservation Reserve Program are being returned to crop production, and with potential consequences for water quality. The objective of this study was to quantify the impact of grassland-to-cropland conversion on nitrate-nitrogen (NO3–N) concentrations in soil and shallow groundwater and to assess the potential for perennial filter strips (PFS) to mitigate increases in NO3–N levels. The study, conducted at the Neal Smith National Wildlife Refuge (NSNWR) in central Iowa, consisted of a balanced incomplete block design with 12 watersheds and four watershed-scale treatments having different proportions and topographic positions of PFS planted in native prairie grasses: 100% rowcrop, 10% PFS (toeslope position), 10% PFS (distributed on toe and as contour strips), and 20% PFS (distributed on toe and as contour strips). All treatments were established in fall 2006 on watersheds that were under bromegrass (Bromus L.) cover for at least 10 yr. Nonperennial areas were maintained under a no-till 2-yr corn (Zea mays L.)–soybean [Glycine max (L.) Merr.] rotation since spring 2007. Suction lysimeter and shallow groundwater wells located at upslope and toeslope positions were sampled monthly during the growing season to determine NO3–N concentration from 2005 to 2008. The results indicated significant increases in NO3–N concentration in soil and groundwater following grassland-to-cropland conversion. Nitrate-nitrogen levels in the vadose zone and groundwater under PFS were lower compared with 100% cropland, with the most significant differences occurring at the toeslope position. During the years following conversion, PFS mitigated increases in subsurface nitrate, but long-term monitoring is needed to observe and understand the full response to land-use conversion.
Access
Open
Rights
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.
Language
en
File Format
application/pdf
Recommended Citation
Zhou, Xiaobo; Helmers, Matthew J.; Asbjornsen, Heidi; Kolka, Randy; and Tomer, Mark D., "Perennial Filter Strips Reduce Nitrate Levels in Soil and Shallow Groundwater after Grassland-to-Cropland Conversion" (2010). Agricultural and Biosystems Engineering Publications. 318.
https://lib.dr.iastate.edu/abe_eng_pubs/318
Included in
Agriculture Commons, Bioresource and Agricultural Engineering Commons, Natural Resource Economics Commons, Natural Resources Management and Policy Commons
Comments
This article is from Journal of Environmental Quality 39, no. 6 (November 2010): 2006–2015, doi:10.2134/jeq2010.0151.