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Nitrogen management in no-till winter wheat production systems [electronic resource] /

by Gaidos, Joan Marie

Abstract (Summary)
Determining optimum N fertilization rate and timing is critical to improve yields and economic sustainability for no-till winter wheat (Triticum aestivum L.) in the Virginia Coastal Plain. Little data are available evaluating N management strategies, optimum N rate prediction methods, or potential NO3 leaching under no-till wheat in soils and climate similar to the mid-Atlantic region. The objectives of our research were: (1) to determine economic optimum N fertilization rates and timings; (2) evaluate selected methods for predicting optimum N rates at GS 25 and GS 30; and (3) measure NO3 leaching loss under selected N management strategies. Eleven experiments over three years evaluated N rates at GS 25 and GS 30. Six experiments over two years evaluated pre-plant and December or GS 25 N rates under no-till winter wheat in farm fields of the Coastal Plain region of Virginia. Nitrate leaching was measured under selected pre-plant and December or GS 25 N application rates. All sites represented common Coastal Plain soil types and cultural practices for no-till wheat production. Yield data were used to calculate economic optimum N rates for a range of combinations of N management strategies. Optimum N rates were regressed against tiller density at GS 25, and wheat tissue N content and SPAD chlorophyll meter readings at GS 30, to determine their effectiveness as predictors of the optimum N rate at GS 25 or GS 30. Tiller density was an effective predictor of optimum GS 25 N rate in these split application management strategies.
Bibliographical Information:

Advisor:

School:Virginia Polytechnic Institute and State University

School Location:USA - Virginia

Source Type:Master's Thesis

Keywords:wheat nitrogen leaching no till

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