AuthorNimry, Bassam Saad,1933-
Committee ChairDutt, Gordon R.
McIntosh, Thomas H.
MetadataShow full item record
PublisherThe University of Arizona.
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.
AbstractThe objective of this study was to evaluate potential denitrification in nitrate-containing waters percolating through the soil. Laboratory studies were conducted in 5bil columns. The extent of denitrification was studied under two different soil conditions, 1. Pure sand, and 2. Pure sand interbedded, at one location, with 15 centimeters of a finer texture soil material. The treatments included the addition of nitrate alone, sugar (sucrose) alone and sugar + nitrate. Under the conditions of the experiments performed, no nitrate disappeared without the presence of an energy source. Based on this finding, the nitrate loss was attributed to respiratory nitrate reduction and immobilization by microorganisms during the oxidation of the added sugar. In the treatments with different combinations of sugar and nitrate the total amount of NO(3)-N that disappeared varied between 14 and 37 percent. The amount of NO(3)-N that disappeared depended on the concentrations of both NO(3)-N and sugar added. It was concluded from the gas analyses, redox potentials and pH values, that the distribution of sugar and nitrate when added with water took place above the anaerobic zone that developed beneath the soil layer. This conclusion meant that the major nitrate utilization by microorganisms took place in an overall aerobic condition, where only the small anaerobic pores exerted the most influence on nitrate loss.
Degree ProgramAgricultural Chemistry and Soils