Agronomy Journal Grow Your Career With ASA
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Published online 1 March 1966
Published in Agron J 58:175-178 (1966)
© 1966 American Society of Agronomy
677 S. Segoe Rd., Madison, WI 53711 USA
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Brown, M. J.
Right arrow Articles by Pratt, P. F.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Brown, M. J.
Right arrow Articles by Pratt, P. F.
Agricola
Right arrow Articles by Brown, M. J.
Right arrow Articles by Pratt, P. F.

Effect of Temperature and Coating Thickness on the Release of Urea from Resin-Coated Granules1

M. J. Brown, R. E. Luebs and P. F. Pratt2

Resin coatings are very effective in controlling the availability of N from applied urea in moist soil. In leaching studies, 94% of the noncoated urea was recovered in 1 day, compared to a 49% recovery of the N from coated urea (13.2% resin) in 4 weeks of intermittent leaching.

Release rates are controlled by the thickness of the coating and the temperature of the medium. Coatings averaging 13.2% resin markedly decreased release of urea, compared to coatings of 9.0% resin. In the range between 5 to 35C, increased release of urea accompanied increases in temperature. After 4 weeks of incubation and intermittent leaching totaling 20 inches of water, 25 and 67% of the added N were leached from soil at 5 and 35C, respectively. Increasing the temperature 10C was approximately equivalent to doubling the release time within a 16-week period. Increasing the temperature increases expansion of the capsule and the surface area through which diffusion must take place. This effect is probably supplemental to the effect of temperature on the diffusion phenomena per se. Approximately 99% of the capsules were recovered intact after incubation for 16 weeks at four temperatures between 5 and 35C.

1 Contribution from Soil and Water Conservation Research Division, ARS, USDA, and the California Agricultural Experiment Station.

2 Soil Scientist and Research Soil Scientist, USDA, and Professor of Soil Science, University of California, Riverside.

Received for publication August 8, 1965.




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
The SCI Journals Crop Science Vadose Zone Journal
Journal of Natural Resources
and Life Sciences Education		 Soil Science Society of America Journal
Journal of Plant Registrations Journal of
Environmental Quality		 The Plant Genome
Copyright © 1966 by the American Society of Agronomy.