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Life Sciences

Nitrogen

University of Northern Iowa

Publication Year

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Corn (Zea Mays L.) Yield Response To Nitrogen Fertilizer In Conventional And Alternative Rotations, M. M. Harbur, M. Ghaffarzadeh, R. M. Cruse Jan 2000

Corn (Zea Mays L.) Yield Response To Nitrogen Fertilizer In Conventional And Alternative Rotations, M. M. Harbur, M. Ghaffarzadeh, R. M. Cruse

Journal of the Iowa Academy of Science: JIAS

Nitrogen (N) fertilization recommendations are not available for corn in rotation with small grains or forages despite the possibility that the N response may differ from that of more conventional corn-soybean rotations. Rotations of corn with soybean (CS), corn with soybean and oat (CSO) and corn with soybean and an oat/berseem clover intercrop (CSOB) were established in 1991 and studied from 1993 through 1998 to determine the optimal N fertilization level for corn produced in each rotation. Corn in each rotation received NH4N03 applied at the rates of 0, 56, 112, or 168 kg N ha-1. Significant differences …


Chlorophyll Meter Assessments Of Corn Response To Nitrogen Management Practices, M. M. Siambi, D. L. Karlen, R. M. Shibles Jan 1999

Chlorophyll Meter Assessments Of Corn Response To Nitrogen Management Practices, M. M. Siambi, D. L. Karlen, R. M. Shibles

Journal of the Iowa Academy of Science: JIAS

Environmentally sound nitrogen (N) management is necessary to simultaneously achieve high crop yields and protect surface and groundwater quality. We evaluated a hand-held chlorophyll meter as a diagnostic tool for improving management for corn (Zea mays L.). Five N fertilizer rates (0, 67, 134, 201 and 280 kg N ha-1) were evaluated in one study, and in a second study, the meter was used to evaluate the N status of corn plants grown under varying tillage (chisel plow vs no-till), crop rotation (continuous corn vs corn-soybean [Glycine max (L.) Merr.]), and N management treatments. Meter readings were …