ARS | Publication request: SIMULATING LATE SPRING NITROGEN TEST EFFECTS ON N LEACHING AND CROP PRODUCTION

Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract
Publication Acceptance Date: November 6, 2003
Publication Date: November 6, 2003
Citation: MALONE, R.W., MEADE, T.G., MA, L., ANAPALLI, S.A., KANWAR, R.S., KARLEN, D.L., HATFIELD, J.L., AHUJA, L.R. SIMULATING LATE SPRING NITROGEN TEST EFFECTS ON N LEACHING AND CROP PRODUCTION. CD-ROM. MADISON, WI. AMERICAN SOCIETY OF AGRONOMY MEETINGS. 2003.

Technical Abstract: Split applications of fertilizer according to soil nitrate testing can reduce nitrate transport off site without reducing corn yield. In fact, this is recommended in many states as a best management practice (BMP) for corn and is sometimes called the pre sidedress soil nitrate test (PSNT) or the late spring nitrate test (LSNT). The effects of this management practice under different conditions (soil, climate, etc.), however, are uncertain. Also, some difficulties of the LSNT include: determination of optimum N application rates and timing, and applying fertilizer within an acceptable timeframe after soil testing. A model that accurately simulates soil C/N cycling, nitrate leaching, and crop yield could help solve these problems. The objective of this research was to compare six years of observed data from twelve one acre subsurface drained plots located in northeast Iowa under two managements (LSNT and single N application) to RZWQM simulations. Results suggest that RZWQM is a promising tool to quantify the effects of LSNT in comparison to more traditional management (single N application).