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ARS Home » Midwest Area » Morris, Minnesota » Soil Management Research » Research » Publications at this Location » Publication #93224
Title: ENHANCEMENT OF THE DECISION AID FOR PREDICTING NITROGEN FERTILIZER NEEDS

Author
item MATTSON, NEIL - UNIVERSITY OF MINNESOTA
item Olness, Alan
item LOPEZ, DIAN - UNIVERSITY OF MINNESOTA
item SWEENEY, COLLIN - UNIVERSITY OF MINNESOTA
item CORDES, JASON - MTS SYSTEMS CORP.

Submitted to: Minnesota Academy of Science Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/2/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Agricultural N use efficiency ranges from about 30% to 70% of each annual application. Improved N use efficiencies would improve profitability and reduce risk of environmnetal pollution. The purpose of this work was to incorporate 1) an improved bulk density subroutine into a N fertilizer decision aid, 2) an improved temperature routine, and 3) test these changes sagainst observed changes of soil nitrate-N for 6 sites in Pope County, and 8 no tillage (NT) and 8 conventional tillage (CT) sites in Rock County. For the Pope County sites the mean observed change of nitrate was -2.07 +/- 0.55 ug per g soil. The mean predicted change was 17.7 +/- 4.72 ug per g soil using the old bulk density and soil temperature functions and 8.08 +/- 0.99 ug per g soil using the new functions. For the Rock County sites, the mean observed change was -0.07 +/- 2.13 ug per g soil (NT) and -0.71 +/- 0.90 ug per g soil (CT). The mean predicted change was 2.02 +/- 1.86 ug per g soil(NT) and 3.22 +/- 2.69 ug per g soil(CT)using the old functions and 2.09 +/- 2.05 ug per g soil(NT)and 3.19 +/- 2.26 ug per g soil(CT) using the new functions. Changes made to the soil temperature and bulk density functions generally enhanced the ability of the decision aid to predict changes in soil nitrate nitrogen.