HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ernst, J. W. Articles by Massey, H. F. Search for Related Content PubMed Articles by Ernst, J. W. Articles by Massey, H. F. Agricola Articles by Ernst, J. W. Articles by Massey, H. F.

The Effects of Several Factors on Volatilization of Ammonia Formed from Urea in the Soil¹

ABSTRACT

The effects of several environmental factors on the volatilization of ammonia from surface applications of urea on Dickson silt loam soil were studied under laboratory conditions.

Increasing temperature and/or soil pH markedly increased ammonia volatilization.

Ammonia volatilization from pH 6.5 soil was essentially the same when urea was topdressed, mixed with the top inch of soil or topdressed and watered into the soil with inch of water. Thus, it may be assumed that urea diffused through the soil to approximately the same extent with each of the three treatments.

Some ammonia volatilization occurred without a concurrent drying process in the soil, but greater volatilization occurred when moisture was lost from the soil. The drying rate, however, varied over a wide range without affecting the rate of ammonia volatilization. Under conditions of very rapid drying, the soil became dry after 4 to 5 days of aeration, and ammonia volatilization was markedly decreased, presumably because hydrolysis of the urea was retarded due to lack of moisture.

Ammonia volatilization was found to be directly related to initial soil moisture content presumably through the effect of this variable on the duration of the drying process.

¹ Contribution from the Department of Agronomy, Kentucky Agr. Exp. Sta., Lexington. Published with the approval of the Director of the Kentucky Agr. Exp. Sta. Grateful acknowledgement is made of financial assistance from the Nitrogen Division, Allied Chemical Corp. Presented before Div. II, Soil Science Society of America, Nov. 17, 1959, at Cincinnati, Ohio.

² Former Graduate Assistant and Professor of Agronomy, respectively.

Received for publication July 10, 1959. Accepted for publication October 21, 1959.