Validation of Nitrogen Calibration Strip Technology for Prescribing Accurate Topdress Nitrogen Fertilizer

Abstract

The purpose of this study was to determine a method of determining Nitrogen rate recommendations midseason by the use of preplant N strips (called the nitrogen calibration strips) by using both visual observations and optical sensor measurements. From the results obtained in this experiment from a two year period temporal variability was a major factor. Many of the sites may have shown no significant difference from the added topdress treatments therefore added N would have not had a significant increase in yield. The use of preplant NCS is a good indicator of the amount of N to apply although when making a visual indication of how much N should be applied requires more preplant N rates than just three rates. From many of the trails that were conducted in farmer fields there was adequate amounts of N put on preplant to carry the wheat crop through maturity.