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George N. Hoffer papers

 Collection — Box: Communal Collections 24, Placement: 12
Identifier: MSF 177

Scope and Contents

The collection is comprised of one folder with publications by George Hoffer.


  • 1918 - 1920


Language of Materials

Collection materials are in English.

Access Information

The collection is open for research.

Copyright and Use Information

Some material in this collection is in the public domain, while other material copyrights are held by Purdue University. Consult with Purdue University Archives and Special Collections prior to reproduction of materials.

Biographical Information

George Hoffer, a chemist, came to Purdue to be a botanist. He was a professor of Biology. He led research starting with black flecks appearing in canned corn and ending with the discovery of extreme K deficiency in the soil. The black flecks were iron oxides. The corn kernels were two times normal in iron. The nodes on the stalks had black zones very high in iron. The soils were acid and low in P but liming and phosphorus did little good. There was a lot of fungus in the plant, but that wasn't the problem. Finally a North Carolina farmer pleaded for help. His 75 bushel corn fields were now yielding very little. Hoffer suggested including some crude sulfate of potash in a simple field experiment. Presto...the K tripled yields and it eliminated the flecks, the dark discolored nodes, the lodged stalks, and the prolific fungus growth.

Hoffer spread the word. K was deficient in all soils east of the Mississippi River. Rainfall is high and K can be leached out. Well, not everyone learned this lesson; so Hoffer, in his eighties still needed to push potash.

It is said that..."We Purdue types sample our soils with our "Hoffer" tubes while the rest of the world simply calls them sampling tubes."


0.025 Cubic Feet (One folder)


The material is in chronological order.

Immediate Source of Acquisition

Source and date of acquisition are unknown.

Processing Information

The material is housed in an acid-free folder and an acid-free box.
George N. Hoffer papers
Mary A. Sego
Description rules
Describing Archives: A Content Standard
Language of description
Script of description
Edition statement
Second edition. Collection description first completed 2010..

Repository Details

Part of the Purdue University Archives and Special Collections Repository

504 Mitch Daniels Boulevard
West Lafayette Indiana 47907 United States