Nitrogen cycling in irrigated crop production on hyperthermic soils within the Sonoran Desert

Persistent Link:
http://hdl.handle.net/10150/191205
Title:
Nitrogen cycling in irrigated crop production on hyperthermic soils within the Sonoran Desert
Author:
McGee, Eric Arthur.
Issue Date:
1996
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Nitrogen (N) cycling involves the gains, losses, and transformations of N from sources such as soil organic matter, crop residues, and fertilizers. These sources are the primary N supplies potentially available to non-leguminous crops. Through the use of a stable N isotope tracer (¹⁵N), transformations among various soil N pools can be studied. We conducted three separate studies using ¹⁵N. Two studies dealt with methodologies of ¹⁵N use and analysis, while the third study investigated mineralization of ¹⁵N labeled crop residues under field conditions. The first study evaluated a new apparatus for applying ¹⁵N by fertigation to subplots under buried drip irrigation. We determined that this method was an effective means of uniformly applying tracers using buried drip irrigation. The second study evaluated a new method for fine-grinding soils based on particle size distribution and variability of organic N and ¹⁵N analyses. Soils of varying texture were rapidly ground to achieve acceptable analytical precision for N and ¹⁵N analysis. The objectives of the third experiment were to: (i) evaluate mineralization of inorganic N from ¹⁵N -labeled crop residues with different C/N ratios and at different loading rates and (ii) evaluate the influence of residue loading rate and type on the percent net mineralization from ¹⁵N-labeled crop residues in a basin irrigated wheat cropping system in Southern Arizona. Mineralization of crop residues in this hyperthermic soil was rapid and was often followed by periods of re-immobilization. Net end-of-season mineralization of residue N was 30-50% for lettuce, and 30-40% for wheat.
Type:
Dissertation-Reproduction (electronic); text
Keywords:
Hydrology.; Irrigation farming -- Sonoran Desert.; Nitrogen cycle.
Degree Name:
Ph. D.
Degree Level:
doctoral
Degree Program:
Soil, Water, and Environmental Science; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Thompson, Tom L.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleNitrogen cycling in irrigated crop production on hyperthermic soils within the Sonoran Deserten_US
dc.creatorMcGee, Eric Arthur.en_US
dc.contributor.authorMcGee, Eric Arthur.en_US
dc.date.issued1996en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractNitrogen (N) cycling involves the gains, losses, and transformations of N from sources such as soil organic matter, crop residues, and fertilizers. These sources are the primary N supplies potentially available to non-leguminous crops. Through the use of a stable N isotope tracer (¹⁵N), transformations among various soil N pools can be studied. We conducted three separate studies using ¹⁵N. Two studies dealt with methodologies of ¹⁵N use and analysis, while the third study investigated mineralization of ¹⁵N labeled crop residues under field conditions. The first study evaluated a new apparatus for applying ¹⁵N by fertigation to subplots under buried drip irrigation. We determined that this method was an effective means of uniformly applying tracers using buried drip irrigation. The second study evaluated a new method for fine-grinding soils based on particle size distribution and variability of organic N and ¹⁵N analyses. Soils of varying texture were rapidly ground to achieve acceptable analytical precision for N and ¹⁵N analysis. The objectives of the third experiment were to: (i) evaluate mineralization of inorganic N from ¹⁵N -labeled crop residues with different C/N ratios and at different loading rates and (ii) evaluate the influence of residue loading rate and type on the percent net mineralization from ¹⁵N-labeled crop residues in a basin irrigated wheat cropping system in Southern Arizona. Mineralization of crop residues in this hyperthermic soil was rapid and was often followed by periods of re-immobilization. Net end-of-season mineralization of residue N was 30-50% for lettuce, and 30-40% for wheat.en_US
dc.description.notehydrology collectionen_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.typetexten_US
dc.subjectHydrology.en_US
dc.subjectIrrigation farming -- Sonoran Desert.en_US
dc.subjectNitrogen cycle.en_US
thesis.degree.namePh. D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineSoil, Water, and Environmental Scienceen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairThompson, Tom L.en_US
dc.contributor.committeememberDoerge, Thomas A.en_US
dc.contributor.committeememberLong, Austinen_US
dc.contributor.committeememberQuade, Jayen_US
dc.contributor.committeememberOlsen, Mary W.en_US
dc.contributor.committeememberPost, Donald F.en_US
dc.identifier.oclc213358732en_US
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