Author
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Bausch, Walter |
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Brodahl, Mary |
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Submitted to: International Conference on Precision Agriculture Abstracts & Proceedings
Publication Type: Abstract Only Publication Acceptance Date: 1/31/2008 Publication Date: 7/21/2008 Citation: Bausch, W.C., Brodahl, M.K. 2008. Reference Strip Evaluation for In-Season Plant Nitrogen Assessment in Irrigated Corn. International Conference on Precision Agriculture Abstracts & Proceedings. Interpretive Summary: Technical Abstract: Reference Strip Evaluation for In-Season Plant Nitrogen Assessment in Irrigated Corn The sufficiency index approach for assessing plant nitrogen (N) status is based on the presence of a reference strip in the field to normalize measurements made in the target area of the field. Early work conducted in Nebraska indicated that several reference strips should be established in each field with adequate N applied to these strips to insure that plants in the reference do not exhibit an N deficiency. Farmers interested in implementing this approach to improve N use efficiency have indicated resistance to the use of reference strips due to the additional effort required to establish and maintain them. This paper addresses the “goodness” of reference strips used in commercial center pivot-irrigated corn fields in eastern Colorado for assessment of plant N status. Analyses were conducted to determine N sufficiency within the reference strip. Evaluations were based on (1) using the average value for the reference strip regardless of soil texture differences in the field and (2) consideration of soil texture effects on crop productivity by using apparent electrical conductivity (ECa) as a surrogate for soil texture. Results indicated that a lot of variability can exist within a reference strip as one might expect, the reference strip did not always meet the criteria expected of reference strips, and soil effects on crop productivity must be included if different soils exist in the field. |
