Everything about Hans Jenny Pedologist totally explained
» For the wave phenomena scientist, see Hans Jenny (cymatics).
Hans Jenny (
7 February 1899 –
9 January 1992) was a soil scientist and expert on
pedology (the study of
soil in its natural environment), particularly the processes of soil formation.
Overview
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, 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 be other
variables in the
function.
In
The Soil Resource, Origin and Behaviour (1980), Jenny redefined the soil forming factors as
state variables and extended the effects to
ecosystem properties. Parent material and relief define the initial state for soil development, regional climate, and potential biota determine the rate at which chemical and biological transformations proceed, and time determines the reach of these processes, and their expression in ecosystem, soil, vegetation, and animal component properties.
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's 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 don't wish to accelerate humus oxidation and the concomitant flux of
carbon dioxide from soil into the atmosphere. I'm 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."
Bibliography
- 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 (1980) The Soil Resource, Origin and Behaviour, Springer-Verlag, New York.
- 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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