Hans Jenny (pedologist)
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- ''For the wave phenomena scientist, see Hans Jenny (cymatics).
Hans Jenny was born in Basel, Switzerland. He earned a diploma in agriculture from the Swiss Federal Institute of Technology (ETH Zurich) in 1922, and a D. Sc. degree in 1927 for a thesis on ion exchange reactions.
Following an appointment at the University of Missouri (Columbia), he joined the faculty at Berkeley in 1936. International recognition came to Jenny after the 1941 publication of Factors of Soil Formation. His synthesis of field studies with the abstract formalism of physical chemistry set down the generic mathematical relationship that connects the observed properties of soil with the independent factors that determine the process of soil formation:
s = f(cl, o, r, p, t, ...)
where s - soil properties; cl - regional climate; o - potential biota, r - topography; p - parent material; t - time
Jenny left the ellipsis open to indicate that there might other variables in the function.
One notable project was his study of Pygmy forest, a remarkable community of ericaceous and coniferous plant species whose stunted growth and grotesquely twisted morphology reveal a long and tortured struggle for survival on a 500,000 year old marine in Mendocino County, California.
Jenny applied fundamental soil science to the problems of the day, when he wrote about "the rosy outlook that is sweeping the nation about converting biomass to alcohol and gasohol...We are promised construction of ingenious machines that will pick up all crop residues in the fields and leaf litter and humus in the forests. The carbon and nitrogen cycles of ecosystems will be curtailed and soil stability endangered. Because of a possible climatic warm-up, we do not wish to accelerate humus oxidation and the concomitant flux of carbon dioxide from soil into the atmosphere. I am arguing against indiscriminate conversion of biomass and organic wastes to fuels. The humus capital, which is substantial, deserves being maintained because good soils are a national asset."
References
- [University of California, Hans Jenny, in memoriam]
- Amundsen, R., 2004, [History of Soil Science: Hans Jenny], pdf format, in Encyclopedia of Soils in the Environment. Hillel, D., J.L.. Hatfield, D.S. Powlson, C. Rosenweig, K.M. Scow, M.J. Singer and D.L. Sparks. Editors. (2004) Four-Volume Set, Volume 1-4, ISBN 0-12-348530-4
Books authored
- Jenny, Hans (1929) Relation of temperature to the amount of nitrogen in soils. Soil Science 27: 169–188.
- Jenny, Hans (1936) Simple kinetic theory of ionic exchange. I. Ions of equal valency. Journal of Physical Chemistry 40: 501–507.
- Jenny, Hans (1961) E.W. Hilgard and the Birth of Modern Soil Science. Pisa, Italy: Collana della Rivista ‘‘Agrochimia.’’
- Jenny, Hans (1968) The image of soil in landscape art, old and new. Pontifical Academy of Sciences Scripta Varia 32: 947–979.
- Jenny, Hans (1989) Hans Jenny. Soil Scientist, Teacher, and Scholar. Regional Oral History Office, The Bancroft Library, University of California–Berkeley, CA.
- Jenny, Hans (1994) [Factors of Soil Formation.] A System of Quantitative Pedology. New York: Dover Press. (Reprint, with Foreword by R. Amundson, of the 1941 McGraw-Hill publication). pdf file format.
- Jenny, Hans and K. Stuart (1984) My friend, the soil. Journal of Soil and Water Conservation 39: 158–161.
- Jenny, Hans, R. Overstreet, and A.D. Ayers (1939) Contact depletion of bare roots as revealed by radioactive indicators. Soil Science 48: 9–24.
- Jenny, Hans, T.R. Nielsen, N.T. Colemna, and D.E. Williams (1950) Concerning the measurement of pH, ion activities, and membrane potentials in colloidal systems. Science 112: 164–167.
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