Long-Term Drainage and Nitrate Leaching below Well-Drained Continuous Corn Agroecosystems and a Prairie

• Published in: Journal of environmental protection (Irvine, Calif.) Calif.), 2014-03, Vol.5 (4), p.240-254
• Main Authors: Masarik, Kevin C., Norman, John M., Brye, Kristofor R.
• Format: Article
• Language: English
• Subjects: Zea mays
• ISSN: 2152-2197; 2152-2219
• DOI: 10.4236/jep.2014.54028

Many studies have evaluated nitrate-N leaching from tile-drained agricultural soils, but little long-term research has been performed on well-drained soils commonly throughout the Midwest. Equilibrium tension lysimeters installed at a depth of 1.4 m were used to measure year-round (12 month) nitrate-N leaching below chisel-plow (CP) and no-tillage (NT) continuous corn (Zea mays L.) agroecosystems to determine the potential effects of common agricultural practices on subsurface water quality. The corn systems were fertilized at a rate of 10 kg N ha super( -1) of starter fertilizer and 180 kg N ha super( -1) as NH sub( 4)NO sub( 3). For comparison, nitrate-N leaching from a natural ecosystem was performed on a nearby prairie restoration (PR). Drainage, nitrate-N leaching loss, and flow-weighted mean nitrate-N concentrations for 8 years of data (1996-2003) are reported for the CP, NT and PR ecosystems. Results show that 52%, 37%, 16% of cumulative precipitation was collected as drainage, while 18%, 19%, 0.5% of the total N input was leached as nitrate-N in the CP, NT, and PR, respectively. Nearly three-quarters of the total nitrate-N was leached from each ecosystem during the period from 1 April to 30 June. The 8-yr, flow-weighted mean nitrate-N concentration measured in leachate was 9.5, 12.2 and