Wilhelm Knop

Wilhelm Knop (28 July 1817 – 28 January 1891) was a German agrochemist and pioneer of water culture. Together with Julius von Sachs he identified Nitrogen, Phosphorus, Sulfur, Potassium, Calcium, Magnesium and Iron as essential elements of plant nutrition. In addition, Oxygen, Carbon dioxide and Hydrogen are taken from the air and water, respectively, for respiration and photosynthesis.[1]

Wilhelm Knop
Born(1817-07-28)28 July 1817
Altenau, Lower Saxony, Germany
Died28 January 1891(1891-01-28) (aged 73)
Leipzig, Germany
NationalityGerman
Alma materUniversity of Göttingen
Scientific career
InstitutionsUniversity of Göttingen
University of Heidelberg
University of Leipzig

Knop's nutrient solution, which consists of his four-salt mixture and traces of an iron salt, is still commonly used today.[2] Dennis Robert Hoagland and Daniel I. Arnon proposed that Sachs's solution (1860), Knop's solution (1865), Pfeffer's solution (1900), and Crone's solution (1902) should be supplemented with Boron, Manganese, Zinc, Copper and Molybdenum for best results with water culture experiments.[3][4]

For Knop, the cultivation of crops in nutrient solutions was primarily a method for discovering scientific laws, a principle shared by Dennis Hoagland. For determining the effectiveness of mineral fertilizers, he regarded the field experiment as the authoritative method of investigation.

References
  1. Marschner, Horst (1995). Mineral Nutrition of Higher Plants. ISBN 0124735436.
  2. Mehta, P.; Jajoo, A.; Mathur, S.; Barthi, S. (2010). "Chlorophyll a fluorescence study revealing effects of high salt stress on Photosystem II in wheat leaves". Plant Physiology and Biochemistry. 48 (1): 16–20. doi:10.1016/j.plaphy.2009.10.006. PMID 19932973.
  3. Benecke, W. (1909). "Die von der Cronesche Nährsalzlösung" (PDF). Zeitschrift für Botanik. 1: 235–252.{{cite journal}}: CS1 maint: uses authors parameter (link)
  4. Hoagland & Arnon (1938). The water-culture method for growing plants without soil (Circular (California Agricultural Experiment Station), 347. ed.). Berkeley, Calif.: University of California, College of Agriculture, Agricultural Experiment Station. OCLC 12406778.


This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.