A comparison of methods for evaluating aggregate stability of mountain soils

A comparison of three methods -- Middleton dispersion ratio, wet sieving, and waterdrop impact -- of testing aggregate stability was made. Soil samples were selected from 9 sites representing a wide variety of great soil groups in the Colorado Front Range of the Rocky Mountains at elevations ranging from 5,000 to 11,000 feet. Samples of the top of the A and B horizons were taken. A great variation in stability ranking was found by the different methods. The A and B horizons, although quite different from each other, gave similar responses to the different methods. There was a distinct tendency for the stability rankings of the B horizons to vary less than A horizons, with the different methods. The B horizon was more stable than the A horizon for all soils with the wet sieve test whereas with the waterdrop impact method only one soil had the B horizon more stable than the A horizon; the dispersion ratio test did not detect any significant (5% level) differences between the A and B horizons. The dispersion ratio was the least powerful test in terms of defining differences between soils; the use of 2-3 mm soil instead of <2 mm soil increased the distinguishing power somewhat. The waterdrop impact method was the most powerful test in terms of defining differences between soils. The wet sieve method was intermediate between the dispersion ratio and waterdrop impact methods.

Name thesis:degree_name

Master of Science (M.S.)

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Agronomy

Grantor dc:publisher

Colorado State University. Libraries

Year dc:date.issued

1965

Authors dc:creator

• Chunkao, Kasem, 1938-, author
• Meiman, James R. (James Richard), advisor
• Johnson, Donald D., committee member
• Terwilliger, Charles, Jr., committee member

• Soils -- Research

Statement dc:rights

• Copyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.

Language dc:language.iso

eng, English

Identifier URI

https://doi.org/10.25675/3.025028

OAI identifier oai:identifier

oai:mountainscholar.org:10217/234078