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 Stark, J. M. Articles by Redente, E. F. Search for Related Content PubMed Articles by Stark, J. M. Articles by Redente, E. F. Agricola Articles by Stark, J. M. Articles by Redente, E. F.

Copper Fertilization to Prevent Molybdenosis on Retorted Oil Shale Disposal Piles

Dep. of Soil Science, Univ. of California, Berkeley, CA 94720;

Edward F. Redente

Dep. of Range Science, Colorado State Univ., Fort Collins, CO 80523.

^* Corresponding author.

ABSTRACT

Plants growing on retorted oil shale disposal piles often have Mo concentrations high enough (>8 mg kg^–1) and Cu/Mo ratios low enough (<2.0) to cause molybdenosis in grazing ruminants. High Mo concentrations are present in some plant species in spite of 90 cm of topsoil cover. Copper sulfate was broadcast at rates of 0, 8, 16, and 32 kg Cu ha^–1 on plots with 30 and 90 cm of topsoil over Paraho retorted oil shale to determine if Cu fertilization can increase Cu/Mo ratios in plants so that molybdenosis is no longer a hazard. Of the plant species studied winterfat [Eurotia lanata (Pursh) Moquin], northern sweetvetch (Hedysarum boreale Nutt.), alfalfa (Medicago sativa L.), native grasses [Agropyron smithii Rydb., A. inerme (Scribn. and Smith) Rydb., A. dasystachium, (Hook.) Scribn. and Poa ampla Merr.], and introduced grasses [A. desertorum (Fisch.) Schult., A. intermedlum (Host Beauv.), and Bromus biebersteinii Roem. & Schult.], all except alfalfa showed increased tissue Cu concentrations during the first growing season. Because of high Mo concentrations, however, only winterfat under high fertilization rates developed Cu/Mo ratios sufficient to prevent molybdenosis (i.e., >2.0). By the end of the second growing season, increases in Cu concentrations due to fertilization had declined approximately 30%. These results indicate that although Cu fertilization can be used for short-term improvements in Cu/Mo ratios, it should not be relied upon as the sole technique for preventing molybdenosis on retorted shale disposal piles. Instead, maximum feasible topsoil thicknesses should be used and plant species known to concentrate Mo should be eliminated from seeding mixtures.

Contribution from the Dep. of Range Science, Colorado State Univ.

This work was supported by the U.S. Dep. of Energy under Contract Grant no. DE-AC02-76EV04018.

Received for publication August 2, 1989.