Carl Sprengel

Carl Sprengel

Philipp Carl Sprengel (born March 29, 1787 in Schillerslage , † April 19, 1859 in Regenwalde ) was a German agricultural scientist . With the knowledge of agricultural chemistry he wanted to lead agriculture "towards the highest perfection ". Together with Albrecht Daniel Thaer and Justus von Liebig , he is one of the spiritual pioneers of modern agricultural science .

Years of study and study trips

Carl Sprengel's birthplace in Schillerslage

Carl Sprengel was the son of a Hanoverian postal administrator. He spent his youth on his father's Halbmeierhof. He was tutored by private tutors and had an early desire to become a farmer. At the age of 15 he was one of the first students of Albrecht Daniel Thaer, who had set up an agricultural teaching institute in Celle in 1802 . When Thaer moved his institute to the Prussian Möglin ( Agricultural Academy Möglin ) in 1804 , Sprengel followed his teacher. Until 1808 he worked as an employee at the new Thaersche Institute, most recently as an economic inspector of the Mögliner estate.

Sprengel then worked in agricultural practice for almost ten years, primarily as a consultant on farms in Upper Lusatia, Thuringia, Silesia and Saxony. During this time, however, he mostly spent the winter months in Dresden, where he learned newer languages ​​and attended lectures on chemistry. From 1817 to 1820 he went on extensive study trips to learn about the best farming methods. They took him through many German countries, the Netherlands, France and Belgium and Switzerland. There he also visited the world-famous model farm run by Philipp Emanuel von Fellenberg .

Student and lecturer at the University of Göttingen

Through his teacher Albrecht Daniel Thaer, through his experiences in agricultural practice, through his travels, as well as through the study of specialist literature, Sprengel was convinced that the yields of cultivated plants can only be increased if the new knowledge of the natural sciences is incorporated into the agricultural sector Find practice. According to his understanding, in the future only those who had a scientific education could be successful farmers.

Sprengel decided to become this "perfect" farmer. Although he had already acquired solid scientific knowledge while working at the Thaerian Institute, he still began studying at a university at the age of 34. In 1821 the experienced agricultural practitioner enrolled at the University of Göttingen and became a "student of natural sciences". He studied chemistry, physics, botany, mineralogy, geology and mathematics and attended agricultural lectures. On November 18, 1823, after an excellent examination in chemistry and economics, he was awarded a Dr. phil. PhD.

After completing his doctorate, Sprengel initially stayed in Göttingen. In 1826 he was granted the license to teach. In the winter semester of 1827/28 he gave a five-hour lecture on "Agricultural Chemistry" as a private lecturer, the first lecture on this subject that was given at a German university. In the following years, Sprengel also announced lectures on agriculture. He completed his knowledge of the cultivation methods of cultivated plants that are common in agricultural practice through study trips to all provinces of the Kingdom of Hanover. He also wrote a two-volume textbook on agricultural chemistry. Most of his time, however, he spent in the laboratory of the chemist Friedrich Stromeyer . There he analyzed soils, plants and fertilizers.

Mineral theory and minimum law

In 1826 Sprengel refuted the previously generally accepted humus theory . This theory was based on the assumption that plants can only feed on substances that are similar to them. Humus was considered to be similar to plant matter. However, with new analytical methods, Sprengel was able to prove that the fertilizing effect of the humus is primarily due to the nutrients it contains. For the first time he reported on this finding in the "Journal for the Entire Natural Science" (vol. 8, 1826).

The results of humus research led Sprengel directly to the question of the mineral nutrition of plants. It was primarily through the comparison of data from soil, plant and fertilizer analyzes that he came to the conclusion that the minerals present in plants must be viewed as vital nutrients . His multi-part article, published in 1828 in the “Journal for Technical and Economic Chemistry” under the title “Of the substances in the soil and the subsoil…” was the decisive breakthrough in the modern theory of the mineral nutrition of plants and thus the basis for a scientific one Basics of fertilizer theory.

This article from 1828 also contains the statement that has been forgotten for over a century: “If a plant needs twelve substances for its formation, it will never arise if only one is missing in this number, and it will always grow poorly when one of them is not present in the amount required by the nature of the plant ”(Vol. 3, 1828, p. 93). Sprengel was the first to clearly and unambiguously formulate the “law of the minimum” ( law of the minimum ) - well before Justus von Liebig . However, the important non-material factors such as warmth, light, etc., which Liebig then included, were still missing in this version.

Professor of Agriculture in Braunschweig

Sprengel's activity in Göttingen, conveying scientific knowledge to farmers solely with articles in magazines or textbooks, and making the resulting consequences for fertilization practice accessible, had little success. Sprengel realized that the new doctrine of mineral nutrition would only be accepted in agricultural practice if its correctness can be convincingly demonstrated through appropriate field tests. His repeated initiatives to set up an experimental and model economy serving this main purpose in Göttingen failed, however.

In 1831 Sprengel left Göttingen and moved to Braunschweig. The very advanced Brunswick government planned at the city's Collegium Carolinum set up an Institute of Agriculture and Forestry. Sprengel had accepted the call given to him to help set up this institute and later to take over its management. This seemed to offer him the great opportunity to take over a model farm on his own in order to convince the farmers of the correctness of the new fertilization theory with large-scale field tests.

For various reasons, but mainly due to personal differences between Sprengel and his immediate superior, the establishment of the institute and the provision of test areas were delayed. Therefore, Sprengel initially devoted himself to writing again. From 1834 to 1836 he was editor of the newly founded "Land- und Forstwirthschaftliche Zeitschrift für Braunschweig, Hannover and the neighboring countries". He also published his own articles in this specialist journal. Teaching at the Collegium Carolinum could not begin until the end of 1835. Sprengel, appointed professor in the same year, taught agricultural studies and agricultural chemistry. In the winter semester of 1835/36 he carried out the first agricultural chemistry internship at a German university.

Sprengel's main concern, however, of establishing an experimental economy in Braunschweig in order to demonstrate to farmers the effectiveness of appropriate mineral fertilization through large-scale field tests, remained a pipe dream. Sprengel was only able to set up a small, more or less private test field with the support of the "Agriculture and Forestry Association of Braunschweig". The newly founded institute at the Collegium Carolinum had two domain companies for the practical instruction of the students, but the contact with these companies was exhausted in occasional excursions. Sprengel was not allowed to undertake his own, practical field tests.

Author of groundbreaking textbooks and manuals

In retrospect, however, the fact that Sprengel's wish to take over an agricultural experimental farm on his own did not come true during his work in Braunschweig can be seen as a stroke of luck for the scientific history of agriculture. Within three and a half years, from the autumn of 1835 to the spring of 1839, he wrote three groundbreaking textbooks and handbooks that had a lasting impact on the development of traditional agricultural theory into an agricultural science based on scientific findings.

The first book was published in 1837, The Soil Science or Soil Doctrine . In this work, Sprengel described the different soils not only as geological-mineral weathering products, but above all as locations for the cultivation of cultivated plants. Even today, the diverse interrelationships between rock, soil and plants are shown by Sprengel. He particularly pointed out the importance of the subsoil for plant growth and recommended that the nutrients in the lower soil layers should always be examined in chemical soil analyzes. The work, which also contains instructions for the chemical analysis of arable soils written by the chemist Friedrich Julius Otto , who worked at the Braunschweig Collegium Carolinum , is the first ever scientific textbook on soil science to be oriented towards the needs of agriculture.

Title page of a book by Carl Sprengel

In 1838 Sprengel published The Doctrine of Reclamation and Basic Improvements . In this book he gives a well-founded overview of the methods of converting soils in need of melioration into productive arable and meadow locations. Convinced that only a farmer who is familiar with the methods of the natural sciences can be a successful farmer, Sprengel demanded that only farmers who are also experienced soil and plant experts use the soil estimates necessary for amelioration measures.

Finally, in 1839, The Doctrine of Fertilizer appeared , a handbook on the nutritional theory of cultivated plants with a detailed description of all fertilizers used in agricultural practice at the time. With this book, Sprengel had created such a far-sighted fertilizer theory based on scientific findings that it still largely corresponds to the current doctrine today.

It was certainly not Sprengel's intention to use these three textbooks and handbooks, which are now among the “classics” of scientific agricultural literature, to make sub-areas of agricultural studies independent. He always saw "a closed unit" in agriculture. From a scientific-historical point of view, however, with these three books he decisively promoted the independence of sub-areas of traditional agriculture theory (soil science, cultural technology and plant nutrition).

Fulfillment of the life goal in rain forest

In July 1839, Sprengel followed a call to Prussia. Ludolph von Beckedorff , President of the Pomeranian Economic Society , became his great sponsor. He had made him the offer to become general secretary of his company. Sprengel took up residence in Regenwalde (today: Resko ) and began again, now 52 years old, under much more favorable conditions than eight years earlier in Braunschweig, to realize his plans and ideas. In 1842 he founded a private agricultural teaching institute, which was soon supported with government funds and called itself from 1846 "Landbau-Academie zu Regenwalde". On a large test farm, Sprengel was finally able to carry out large-scale fertilization tests according to his own ideas. He also founded a farm equipment factory, which was a successful business enterprise in Regenwalde until the end of the Second World War .

Despite this, Sprengel continued to be literary in Regenwalde. From 1840 to 1853 he was editor of the newly founded Allgemeine Agricultural Monthly . However, he crowned his scientific life's work with a textbook. The three-volume work published between 1847 and 1852 under the title My Experiences in the Field of General and Special Plant Cultivation is one of the best textbooks for plant cultivation ever written in German. Clearly, clearly and free of speculation, Sprengel has summarized both traditional experience and the new scientific knowledge about the cultivation of the most important Central European crops into a single presentation. The work, which comprises more than 1000 printed pages, is still a real treasure trove of plant cultivation knowledge.

This memorial was erected in Regenwalde in 1881 in memory of Carl Sprengel.

Carl Sprengel also found his personal happiness in Regenwald. On September 30, 1841, at the age of 54, he married 19-year-old Juliane von Wulffen (1822-1859), daughter of a Prussian major. Through this marriage, Sprengel came into close family ties to the Pomeranian nobility. The marriage has a daughter and a son, but little is known about Sprengel's family life, which was founded so late.

Carl Sprengel died of heart failure at the age of 72. After his death, the Landbau-Academie was dissolved and the other facilities he had set up, with the exception of the farm equipment factory, were also closed. In 1881 the Agricultural Association of Regenwalde erected an obelisk on the occasion of its 50th anniversary, which bore the inscription: “In memory of Dr. Carl Sprengel ”. The memorial was badly damaged during World War II. In the course of the EU expansion , a joint initiative by German and Polish agricultural scientists and local politicians succeeded in repairing the war damage with the help of private donations. On June 13, 2004, the restored obelisk was opened to the public again as a memorial to the history of science in Europe. In 2004, a new tombstone with a bilingual text (German-Polish) was erected on the still existing grave of Carl Sprengel in Resko.

Carl Sprengel's grave in Regenwald

Carl Sprengel and Justus von Liebig

For almost a century, Carl Sprengel was one of the “forgotten” agricultural scientists. Little was known about his life and work. His achievements in the field of arable and plant cultivation were hardly noticed and his epoch-making discoveries in the field of plant nutrition were completely overshadowed by the life's work of Justus von Liebig, who was regarded as the actual founder of the theory of the mineral nutrition of plants.

The central importance of Carl Sprengel for the development of modern agricultural science was brought to the public's attention only around 1950 through the research of the agricultural chemist Fritz Giesecke and his pupil Günter Wendt . The results of their historical studies were clear: not the world-famous chemist Justus von Liebig, but the Thaer student Carl Sprengel was the founder of the theory of the mineral nutrition of plants.

This historical fact, which is widely recognized today, in no way detracts from Liebig's great achievements in the field of agricultural chemistry. It was Liebig who, with his popular publications, helped the theory of the mineral nutrition of plants to breakthrough and did a lot to make mineral fertilizers available to farmers. He was the decisive fighter for the recognition of the new plant nutrition theory in agricultural practice.

Nevertheless, the research results of Fritz Giesecke and Günter Wendt caused a sensation in the professional world at the time. Fortunately, a priority dispute over who should be given the greatest merit in the field of modern plant nutrition was fortunately avoided. The Association of German Agricultural Investigations and Research Institutes donated a Sprengel-Liebig Medal in 1954 to document the inseparable merits of both scientists in this field.

Honor

In the Braunschweig district of Völkenrode a street is named after him, the "Karl-Sprengel-Straße" with the postcode 38112.

Major works

• News of Hofwyl in letters. In addition to a draft for agricultural schools. Celle 1819.
• Chemistry for farmers, foresters and cameralists. 2 volumes. Göttingen 1831 and 1832.
• Soil science or the theory of soil, along with complete instructions for the chemical analysis of the soil and the results of 170 chemically examined soil types from Germany, Belgium, England, France, Switzerland, Hungary, Russia, Sweden, the East Indies, West Indies and North America - one Handbook for farmers, foresters, gardeners, creditors and apportionment commissioners. Leipzig 1837, 2nd edition, 1844.
• The doctrine of reclamation and basic improvements, or: Description and explanation of all reclamations and basic improvements that affect swamps, quarries, raised bogs, ponds, heaths, deserts, forests, sand floes, dunes, rocky grounds, fields, meadows and pastures. Leipzig 1838. ( digitized in the digital library Mecklenburg-Western Pomerania)
• The doctrine of fertilizer or description of all vegetable, animal and mineral fertilizer materials used in agriculture, together with an explanation of their mode of action. Leipzig 1839, 2nd edition, 1845.
• My experiences in the field of general and special plant culture. Volume 1, Leipzig 1847, Volume 2, 1850, Volume 3, 1852.

literature

• Löbe:  Sprengel, Karl . In: Allgemeine Deutsche Biographie (ADB). Volume 35, Duncker & Humblot, Leipzig 1893, p. 293.
• Günter Wendt: Carl Sprengel and the mineral theory created by him as the foundation of the new plant nutrition theory. Dissertation math.-nat. Göttingen 1950. (= book: Wolfenbüttel 1950, with picture).
• Soil fertility as the foundation of quality production. Festschrift for the 90th anniversary of the agricultural investigation and research institute Ebstorf (formerly Braunschweig). Edited by F. Giesecke. Uelzen / Hann. 1952. The publication contains several articles by Fritz Giesecke on the life and work of Carl Sprengel and a comprehensive bibliography.
• Ludwig Schmitt: Philipp Carl Sprengel (1787-1859). In: Great Farmers. Edited by Günter Franz and Heinz Haushofer. Frankfurt am Main 1970, pp. 145–155, (with picture).
• Wolfgang Böhm: The Thaer student Carl Sprengel (1787-1859) as the founder of modern plant nutrition. In: Annual issue of the Albrecht Thaer Society. 23, 1987, pp. 43-59 (with picture).
• Wolfgang Böhm: Carl Sprengel as a pioneer in crop science. In: Journal of Agricultural History and Agricultural Sociology. Vol. 35, 1987, pp. 113-119.
• Diedrich Schroeder: Carl Sprengel - 150 years of “soil science”. In: Journal for Plant Nutrition and Soil Science. Volume 150, 1987, pp. 51-53.
• H.-G. Frede: The doctrine of reclamation and basic improvements - a current reminder of the printing of Carl Sprengel's book 150 years ago. In: Journal for cultural technology and land consolidation. Volume 29, 1988, pp. 2-7.
• Wolfgang Böhm: On the current status of Carl Sprengel research. In: Journal of Agricultural History and Agricultural Sociology. Vol. 41, 1993, pp. 11-17 (with bibliography).
• RR van der Ploeg, W. Böhm, MB Kirkham: On the origin of the theory of mineral nutrition of plants and the law of minimum. In: Soil Science Society of America Journal. Volume 63, 1999, pp. 1055-1062 (with picture).
• Wilhelm Römer: Memorial and grave of Carl Sprengel (1787–1859) in Resko (Poland). Restored and given to the public - a report. In: The Golden Plow. Issue 21, 2005, pp. 9-10 (with several illustrations).
• Klaus Dieter Schwenke: Carl Sprengel's theory of minerals, a milestone in the history of agricultural chemistry. In: THAER TODAY. Published by the Fördergesellschaft Albrecht Daniel Thaer e. V. Möglin, Volume 5, 2008, pp. 23-50 (with picture).
• Albrecht Jungk: Carl Sprengel - The founder of agricultural chemistry. A re-appraisal commemorating the 150th anniversary of his death. In: Journal of Plant Nutrition and Soil Science. Volume 172, 2009, pp. 633-636 (with picture).
• Hans-Peter Blume:  Sprengel, Carl. In: New German Biography (NDB). Volume 24, Duncker & Humblot, Berlin 2010, ISBN 978-3-428-11205-0 , p. 751 f. ( Digitized version ).

Web links

Wikisource: Carl Sprengel  - Sources and full texts

• Literature by and about Carl Sprengel in the catalog of the German National Library

Individual evidence

1. ↑ Carl Sprengel died on April 21, 1859 in Stettin. (Botanische Zeitung, Leipzig No. 18 of March 6, 1859, p. 168), not on April 19, 1859 in Regenwalde as it erroneously says in the Allgemeine Deutsche Biographie, Volume 35, p. 293.
2. ^ Carl Sprengel: Chemistry for farmers, foresters and cameralists. Volume 1, Göttingen 1831, p. VI.