Persistent Link:
http://hdl.handle.net/10150/202473
Title:
Quick Tests for Sap Nitrate in Small Grains, Maricopa, 1997
Author:
Ottman, M. J.
Issue Date:
Oct-1997
Publisher:
College of Agriculture, University of Arizona (Tucson, AZ)
Journal:
Forage and Grain: A College of Agriculture Report
Abstract:
Nitrate content of the lower stem tissue of small grains is used as a guideline for nitrogen fertilization. The turnaround time for nitrate analysis in a commercial lab is usually 1 to 3 days. Nitrate quick tests have been suggested as a means of obtaining results on a more timely basis. The quick tests analyze nitrate in the sap or juice squeezed out of the tissue. A nitrate test conducted by a commercial lab is performed on the dried and ground tissue. In this study, I found that the quick tests on plant sap are not as accurate as conventional tests on dried tissue since the moisture content of the fresh plant tissue varies depending on its nitrate content and the growth stage of the plant. We compared the following quick test methods: nitrate test strips, a colorimetric procedure, and a hand held nitrate electrode. Nitrate test strips were not sensitive enough to be useful and were difficult to compare to the color charts. An electronic strip reader could alleviate this difficulty and make the strips a viable option. Colorimetric procedures, or those that rely on nitrate producing a colored solution with certain chemicals added, are not adapted to analyzing plant sap since the green color and organics in the sap interfer with the color produced by the nitrate. The hand held nitrate electrode, or Cardi meter, was the simplest and most accurate method we experimented tested. Quick tests for nitrate in the sap have the following disadvantages: 1) It is not easy to squeeze the sap out of the plant tissue, 2) The sap needs to be diluted to fit into the analytical range of the test, and 3) The moisture content of the tissue needs to be accounted for somehow for the results to be most accurate.
Keywords:
Agriculture -- Arizona; Grain -- Arizona; Forage plants -- Arizona; Barley -- Arizona; Wheat -- Arizona; Barley -- Fertilizer management; Wheat -- Fertilizer management
Series/Report no.:
370110; Series P-110

Full metadata record

DC FieldValue Language
dc.titleQuick Tests for Sap Nitrate in Small Grains, Maricopa, 1997en_US
dc.contributor.authorOttman, M. J.en_US
dc.date.issued1997-10-
dc.publisherCollege of Agriculture, University of Arizona (Tucson, AZ)en_US
dc.identifier.journalForage and Grain: A College of Agriculture Reporten_US
dc.description.abstractNitrate content of the lower stem tissue of small grains is used as a guideline for nitrogen fertilization. The turnaround time for nitrate analysis in a commercial lab is usually 1 to 3 days. Nitrate quick tests have been suggested as a means of obtaining results on a more timely basis. The quick tests analyze nitrate in the sap or juice squeezed out of the tissue. A nitrate test conducted by a commercial lab is performed on the dried and ground tissue. In this study, I found that the quick tests on plant sap are not as accurate as conventional tests on dried tissue since the moisture content of the fresh plant tissue varies depending on its nitrate content and the growth stage of the plant. We compared the following quick test methods: nitrate test strips, a colorimetric procedure, and a hand held nitrate electrode. Nitrate test strips were not sensitive enough to be useful and were difficult to compare to the color charts. An electronic strip reader could alleviate this difficulty and make the strips a viable option. Colorimetric procedures, or those that rely on nitrate producing a colored solution with certain chemicals added, are not adapted to analyzing plant sap since the green color and organics in the sap interfer with the color produced by the nitrate. The hand held nitrate electrode, or Cardi meter, was the simplest and most accurate method we experimented tested. Quick tests for nitrate in the sap have the following disadvantages: 1) It is not easy to squeeze the sap out of the plant tissue, 2) The sap needs to be diluted to fit into the analytical range of the test, and 3) The moisture content of the tissue needs to be accounted for somehow for the results to be most accurate.en_US
dc.subjectAgriculture -- Arizonaen_US
dc.subjectGrain -- Arizonaen_US
dc.subjectForage plants -- Arizonaen_US
dc.subjectBarley -- Arizonaen_US
dc.subjectWheat -- Arizonaen_US
dc.subjectBarley -- Fertilizer managementen_US
dc.subjectWheat -- Fertilizer managementen_US
dc.identifier.urihttp://hdl.handle.net/10150/202473-
dc.relation.ispartofseries370110en_US
dc.relation.ispartofseriesSeries P-110en_US
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