Submitted to: Agronomy Society of America, Crop Science Society of America, Soil Science Society of America Meeting
Publication Type: Abstract Only
Publication Acceptance Date: August 1, 2003
Publication Date: November 1, 2003
Citation: Mackown, C.T., Weik, J.C. 2003. Laboratory and quick-test measurement of nitrate in winter wheat forage [abstract]. Agronomy Society of America, Crop Science Society of America, Soil Science Society of America Meeting. Paper No. S08-mackown422650-oral. Interpretive Summary: Abstract Only.
Technical Abstract: Timely and accurate assessment of nitrate concentration in forage and water sources can be used to manage potential risks of exposing livestock to excessive nitrate intake. This research compared a standard laboratory nitrate assay protocol for winter wheat (Triticum aestivum L.) forage samples to a novel biochemical linked laboratory and field-test method, and two quick-test methods that use small hand-held instruments. In addition, the efficiency of a nitrate field-extraction method suitable for fresh wheat pasture samples was evaluated and compared with standard laboratory extraction of oven-dried and ground wheat samples. With nitrate standard additions, the biochemically linked laboratory and field-test methods were the most accurate. Among the quick-test nitrate assays a hand held test strip reflectance meter was easiest to use and only slightly less accurate than the enzyme method. Both of these methods were much less variable and did not over estimate tissue nitrate values, as did a hand held compact nitrate specific electrode meter. The nitrate field-extraction method underestimated tissue nitrate concentration by 18% and requires either improvement in extraction efficiency or proper calibration with dry tissues before it will be useful.