Life and work of Eilhard Alfred Mitscherlich,
from Gerhard Weise, Herbert Kaltofen and Manfred Fechner,
Paulinenauer Working Group for Grassland and Forage Management V., 14641 Paulinenaue
Prof. Dr. phil. Dr. agr. H. c. mult. Eilhard Alfred Mitscherlich was born on August 29, 1874 in Berlin. On his father’s family several pastors and university professors descended since the Reformation. His grandfather, Eilhard Mitscherlich, professor of chemistry at Berlin University, was a world-famous co-founder of modern chemistry. His father, Alfred Mitscherlich, was a medic and earned great merit as a professor, secret medical adviser and surgeon. His maternal grandfather, Carl Ackermann, owned five large manors in the Kurmark and Lower Silesia. “So I was predestined for my profession, for ‘scientific agriculture’ on both sides,” wrote Mitscherlich in his memoirs, published in 1945. Young Mitscherlich’s connection with agriculture was further promoted by the fact that from the age of 11 he often spent the school holidays on the estate of his mother’s youngest brother, Franz Ackermann, in Kutschlau, Schwiebus district. This property, located in the eastern part of the province of Brandenburg was left to him by his uncle in 1940 for ten years by means of a will. Mitscherlich did not have fond memories of his school days. At the wise age of 70 he wrote about this time: “When I was six years old, I went to the pre-school of the French grammar school in Berlin. I was a hard student, and apparently I always had a bad memory for things that weren’t right for me. So it happened that I stayed in Quinta for the first time. When it was repeated in the lower secondary school, where all lessons except German, history and religion were given in French, my parents took me from the French grammar school and took me to the Friedrich grammar school. Since I had to start the lower secondary school all over again, I was apparently too mature for this class: I got the best certificate, but then soon fell and finally after a year, despite having enough certificates, I did not get into the higher class again. When I finally climbed the Obertertia, my class teacher said to me: “Go away, become a shoemaker.” … Then my father made the decision, which was so difficult for all of us, to retire abroad, and so I came to Friedeburg Nm. , where I personalities as teachers, where I worked with joy and at Easter 1895 I passed my high school diploma as the best student. I had spent two and a half years on the school desk! Five times I stayed there for half a year! That annoyed me a lot and had to be caught up again somehow.” We know that the implementation of this resolution was more than successful. Mitscherlich began studying in 1895 when he was 20 ½ years old. Just three years later he received his doctorate with magna cum laude, and six years after starting his studies he successfully completed his habilitation. Mitscherlich began his studies at the University of Kiel in 1895. Here he found a teacher in Prof. Hermann Rodewald who aroused his interest in the mathematical formulation of scientific subject matter and who laid the foundations for a scientific way of working with him. Mitscherlich heard the actual agricultural subjects at the university in Berlin. He attended two semesters of lectures in organic chemistry, bacteriology, animal breeding, farm management, general agriculture, agricultural policy, distillery and brewery in Berlin. Returning to Kiel, he began his doctoral thesis, which, at the suggestion of his teacher Rodewald, dealt with the determination of the warmth that occurs when various soils are wetted. After receiving his doctorate in 1898, Mitscherlich followed his physics teacher and brother-in-law Hermann Ebert to the Technical University in Munich. There he heard lectures on dairy farming and worked experimentally on questions of soil physics for a semester. Back in Kiel, he took on an assistant position at Rodewald and attended lectures on higher mathematics and probability at the university. Mitscherlich pursued his pedological investigations in Kiel determinedly. The work to determine the heat of wetting and to determine the hygroscopicity of the soil made him known in specialist circles at home as well as abroad. With a related thesis Mitscherlich completed his habilitation in 1901 in Kiel for the entire field of agricultural science. For this work he received the Liebig Prize endowed with 1000 RM from the Bavarian Academy of Sciences.
During his private lectureship in Kiel from 1901 to 1906, Mitscherlich held a.o. Lectures on agricultural management. However, he continued to devote himself primarily to soil science. It was during this time that the first edition of his book “Soil Science for Farmers and Foresters” was published. In this, Mitscherlich emphasized the current physical-chemical properties of the soil as being decisive for the yield of the cultivated plants. This book has been expanded in every edition and has become a standard work for specialist science. The 7th edition, published in 1954, summarizes the author’s most important research results. Shortly before Easter 1906, Mitscherlich received, quite unexpectedly, an appointment as associate professor for crop production at the University of Königsberg. He agreed with the hope of only a short stay. However, it became 35 years, the main period of his work. Mitscherlich reported for the first time on vegetation experiments as early as 1903. With this he entered an area of work that was to occupy him intensively for over 50 years. In Königsberg he turned to the study of chemical growth factors. In the chemical soil analysis he tried to only use extractants that are also available to the plants. Consequently, he therefore used carbonated water as an extractant. Among other things, he studied the solution of plant nutrients depending on the CO2 concentration, time and temperature. To this end, he developed methods for determining small amounts of nutrients in the soil extracts. He also worked on identifying the errors that occur during sampling in the field, sampling from the ready-to-use substance, and chemical analysis. Such systematic error analyzes are still of great importance today for research as well as for routine examinations for advice in practice. His own, very intensive work on chemical soil analysis in comparison to his plant physiological investigation results led Mitscherlich to the conclusion that chemical soil analysis is less suitable for determining the need for fertilization than the vegetation experiment. Although he considered the chemical soil analysis to be reasonably useful, if one uses this to for example roughly differentiate the very nutrient-poor soils from the rest. Otherwise, however, he was convinced that the plant physiological determination of the effective P and K quantities in the soil, which he had been developing since around 1922, was far superior to the chemical soil analysis and made quantitative recommendations for P and K fertilization possible. Despite all efforts, Mitscherlich did not succeed during his lifetime to assert himself with his proposals against the proponents of chemical soil analysis. Mitscherlich’s main concern, therefore, to use his plant-physiological methods of soil analysis, was limited to East Prussia and a period of less than two decades. This ultimately contributed to excessive P and K fertilization in Germany. In many cases, the yields could have been achieved with a much lower P and K expenditure if one had consulted Mitscherlich’s plant-physiological methods when measuring the P and K doses. For several years, however, there have been efforts to measure the P and K fertilization on grassland, which largely correspond to Mitscherlich’s conception in terms of the basic concerns. The further contribution on this homepage by Hertwig, Schuppenies and Pickert is an example of this. Within 12 years, in the period from 1909 to 1921, Mitscherlich worked out the law of the growth factors. At the beginning of this work, Mitscherlich was initially concerned with specifying Liebich’s minimum law, which was only qualitatively verbally formulated at the time, i.e., to design it quantitatively and mathematically. The container tests he carried out with increasing doses of P fertilizers showed that the yield curves initially rose steeply and then gradually increased. For the mathematical description of this fact, he proposed a function that ultimately made him known around the world. He called this function at first the “law of physio-human relationships”, later based on Baule‘s “law of action of growth factors”.
Effect factor or effect value, the amount of which should be more or less independent of the other growth factors. From today’s perspective, the function proposed by Mitscherlich is a production function. Mitscherlich was the first to propose a useful production function for the relationship between nutrient supply and yield. Based on Mitscherlich’s results and theses, the mathematician B. Baule formulated the so-called “general law of the growth factors” in 1918. This is a generalization of Mitscherlich’s approach to determine the dependence of the yield on several nutrients or growth factors. The mathematical treatment of income retention, introduced by Mitscherlich, has developed impressively around the world. Production functions are used today for many problems. In addition, dynamic models of plant growth and yield formation have been and are being developed, in which the timing of the processes is given through consideration using modern computer technology. Mitscherlich was a pioneer of this development, which was not yet foreseeable for him at the time. Mitscherlich’s work was largely shaped by basic studies of a natural scientific nature. Although they sometimes seemed to have a very theoretical character, they were mostly aimed directly or indirectly at solving practical questions of plant production. In spite of his very strong scientific inclinations, Mitscherlich finally saw himself as a farmer. Certainly much of his theoretical work remained incomprehensible to the practical farmer. Nevertheless, Mitscherlich enjoyed great respect and trust in practice. In 1923 Prof. Mitscherlich received the offer to take over a research institute for crop science with departments for soil science, plant breeding and plant diseases in Dresden. The offer was extremely cheap. During a large dinner with the President of the East Prussian Province, who was also the curator of the Königsberg University, this upcoming appointment was discussed. In a spontaneous reaction to this announcement, well-known farmers in East Prussia approached Mitscherlich with the suggestion that if Mitscherlich stayed in Koenigsberg they would like to found a company that would give Mitscherlich the opportunity to put his research results into practice. Mitscherlich stayed in Königsberg, and so the Mitscherlich Society was founded in East Prussia. For Mitscherlich, it was the decisive institution for the introduction of his scientific results into the agricultural practice of that time. The Mitscherlich Society set up four vessel test stations for soil examinations in East Prussia, where thousands of soil surveys were carried out annually. The core of these vessel stations were the vegetation vessels designed by Mitscherlich and manufactured by the Baumann brothers in Amberg. According to him, these vessels were the only thing that brought in a personal extra income in all of his work. The license fee for the Mitscherlich vessels was enough to have his three children fully trained. Mitscherlich did not make use of the offer made by the board of the Mitscherlich Society to receive 10% of the company’s income as payment. The nutrient requirements of East Prussian soils were determined with the help of 24,000 vessels. In addition, several culture vessels with different fertilizers were used for each soil sample in the spring. They were sown with oats and harvested when they had ripened. On the basis of the yields determined, a recommendation for future fertilization was calculated using the law of effect of the growth factors. It was particularly effective that the farmers were able to inspect the development status of the plants in the test series carried out with their own soils. These studies gave the farmers in East Prussia important information on how to increase and stabilize their crop yields. The farmers greatly appreciated this.
Vascular stations of this type have also been set up abroad, in various European countries as well as in North and South America, in Japan and in the Soviet Union. The Russian edition of the third edition of his book “The determination of the fertilizer needs of the soil” in the 1930s and, most recently, a book by Kirsanov about Mischerlich’s methods is already highly regarded in the Soviet Union. A seminar held by Mitscherlich in 1931 for Soviet specialists at the University of Königsberg was to be significant for him even after the end of the war. The Mitscherlich vessels are still used today in many research institutions. Mitscherlich’s love and close ties to agriculture and his high level of productivity remained unbroken even after his retirement in 1941. He took over the management of the approximately 700 hectare family estate in Kutschlauf, and continued to develop scientifically there. He set up a laboratory and a small container station on the estate, and after examining the soils of all fields on his farm, he wanted to show that the plant yield can be increased by 50% with the right fertilization alone. With this, he wanted to implement his findings and methods of soil investigation in practice. The war events brought an abrupt end to this phase of life in 1945. Mitscherlich left Kutschlau on January 29th, 1945. Two days later he crossed the Oder near Fürstenberg on his trek. This uncertain journey went past Berlin to Siedersdorf in the Ruppiner Land. There Mitscherlich and his companions waited at Farmer Pein’s for the Red Army to march in and for Hitler’s Germany to surrender. The Mitscherlich family had lost almost everything as a result of their flight – besides their personal belongings and goods, among other things also valuable scientific documents. Immediately after the war ended, Mitscherlich contacted the Soviet authorities. He wanted to go back to Kutschlau and also received a document from the Soviet commander on which he and his company were certified protection and assistance. The return journey was extremely difficult, the main roads were blocked. Mitscherlich and his people came to Vietznitz in the Westhavelland district on May 20th via side streets. When Mitscherlich inquired about the further way there at the estate, the estate manager read the nameplate on Mitscherlich’s car. He asked if he was the soil scientist Mitscherlich and suggested that he stay in Vietznitz for the time being and wait for the streets to clear. Mitscherlich agreed to it and moved his trek into a barn. During an officers’ meeting in the Vietznitz manor house, Mitscherlich, who was sitting on a bench, was approached by a Soviet officer who spoke German well. He had recognized his former university professor from Königsberg. These incidents are likely to have been one of the decisive factors in the fact that Mitscherlich and his companion were accepted into the Paulinenaue estate, which was under Soviet military administration. On July 27th, 1945, the treck moved from Vietznitz to Paulinenaue. Immediately afterwards, Mitscherlich and his companions began working in a wide variety of work areas at the Paulinenauer estate. Mitscherlich himself initially worked as an advisor to the officers of the Soviet army in the estate administration, and was particularly interested in the work in the gardening. Despite his advanced age, Mitscherlich faced the challenges of the post-war period at the age of over seventy. Gratefully and with admirable willpower, he took the opportunity to participate as an agricultural scientist in overcoming the consequences of the war in agriculture. In the last phase of his life he devoted himself intensively to the implementation of his extensive knowledge in agricultural practice. His first activities in 1945 were land radio broadcasts on current issues of increasing crop yields. After the Berlin University reopened in 1946, he was appointed to the chair of cultural engineering and director of the institute. But he strove for better conditions for the implementation of his research results in practice than they were in Berlin. He therefore submitted the proposal to the Academy of Sciences, of which he had become a member in 1947, to create a new research institute outside Berlin, directly on a larger farm, thinking of Gut Paulinenaue.
After Mitscherlich’s first retirement in 1941 in Königsberg, his second took place in Berlin in 1950. Based on the emergency situation after the war, Mitscherlich’s letter to the German Academy of Sciences contained concrete proposals for the establishment of a “research institute to increase plant yields” in Paulineaue. Thanks to his convincing arguments and persistent, intelligent negotiations, the new academy institute was founded on June 1st, 1949 in Paulinenaue, the estate was assigned as an experimental estate and Prof. Mitscherlich was appointed director of this facility. The work could begin and Mitscherlich began to implement his concept. Given the material and technical requirements of that time, great efforts were required to acquire Mitscherlich vessels, to set up a vessel station, to erect a laboratory building and to equip it with laboratory technology, to create the conditions for carrying out field tests and to provide apartments for the employees of the institute and the test site to build. Despite all the obstacles and arduous circumstances, the work progressed well. Despite the breadth of the work at the institute, the focus was on research to increase plant yields. An important concern of Mitscherlich in Paulinenaue was to make the plant physiological methods of soil analysis for P and K developed by him effective in practice. He hoped to initiate the use of these methods through the institute – if possible throughout Germany. In the test farm he checked his plant physiological methods for measuring P and K fertilization. Based on his law of action of growth factors, Mitscherlich also attached great importance to work on nitrogen. Further work in Paulinenaue concerned, among other things, the water balance of the soil and vegetation depending on the weather, the cultivation of catch crops and questions of soil physics. Opinions were also repeatedly given on the methodology and the evaluation of field tests. Last but not least, Mitscherlich in Paulinenaue also dealt with the mathematical representation of yield formation depending on the nutrient supply. He dealt in particular with the effect factor or effect value c in his effect law of growth factors. As already mentioned, the effect value c, which is characteristic for each nutrient or growth factor, was originally assumed by Mitscherlich to be constant, that is, to be independent of all other growth factors. But as early as the 1920s, experimental results by Rippel and others showed that the effect value c for a nutrient is smaller, the higher the supply of a second nutrient or the higher the maximum yield A in Mitscherlich’s law of action. Regardless of this, Mitscherlich stubbornly stuck to his view that the action value c is constant for every nutrient. This is especially true because at that time people looked at the gifts according to Mitscherlich’s plant physiological method and Mitscherlich did not want to see under any circumstances questioned the practical application of his law of action of growth factors in the measurement of P and K fertilization. In the further course, however, one gradually came to the conclusion that an absolute constancy of the effect values is not absolutely necessary for the practical application of the effect law of the growth factors in the plant-physiological soil analysis. Not least because of this, Mitscherlich finally gave in to a large extent. In 1953, during a lecture at the conference of the German Soil Science Society, he stated the following: “If a second growth factor is also available in a relatively smaller amount, so that the maximum yield A that can be achieved with the first growth factor is relatively low, then the effect factor c is this first growth factor higher; it decreases the more favorable all other growth factors are, the higher the value A becomes, and that again probably logarithmically until it gradually approaches a minimum level and then remains the same, is “constant”. If we make all other growth factors as favorable as possible in container tests or if we give sufficient basic fertilization of all other nutrients in field tests so that the value A is relatively high, then the effect value c of the individual growth factor is in fact constant.” Looking back, we can sum up: In just a few years, Mitscherlich succeeded in setting up a research facility in Paulinenaue that met the demands of the time. His work in Paulinenaue was the culmination of a long life as a researcher. The fact that at an advanced age he was given the opportunity to set up a research institute at the Academy of Sciences was in his favor.
Literature:
Atanasiu, N.: E. A. Mitscherlich zum Gedenken. – In: Plant and soil. – 8(1956)1.- S. 4 -9
Bredel, O., H. Kaltofen: Eilhard Alfred Mitscherlich 1874- 1956: Leben und Werk. – Berlin u. Paulinenaue, 1998 (Diese Biografie kann bezogen werden über den Paulinenauer Arbeitskreis Grünland und Futterwirtschaft e. V., Gutshof 7, 14641 Paulinenaue)
Kaltofen H.: Eilhard Alfred Mitscherlich – ein weltweit bekannter Gelehrter als Begründer der Agrarforschung in Paulinenaue. – In: 50 Jahre Wissenschaftsstandort Paulinenaue: Wiss. Vortragstagung. – Paulinenaue, 1999. – S. 17- 35
Kirsanov, A.T.: Teorija Micerlicha, ee analiz i prakticeskoje primenenie. – 1. Izd, – Moskva, 1930
Mitscherlich, E., G. Mitscherlich: Eilhard Alfred Mitscherlich (1874- 1956). – In: Die Albertus- Universität zu Königsberg und ihre Professoren . –Berlin, 1995. – S 691 -699. – (Jahrbuch der Albertus- Universität zu Königsberg, Pr.; Bd. 29 = 1994)
Mitscherlich, E.A., E. v. Boguslawski, A. Gutmann: Studien über die Ernährung der Pflanze und die Ertragsbildung bei verschiedener Düngung. – Halle (Saale), 1935. – (Schriften der Königsberger Gelehrten Gesellschaft: Naturwissenschaftliche Klasse; Jg. 12, H2)
Mitscherlich, E.A.: Lebenserinnerungen. – Halle (Saale), 1945. – (Selbstbiographien von Naturforschern: Nr. 3)
Mitscherlich, E. A.: Über die Fehler bei Ertragsversuchen. – Berlin, 1950. – (Vorträge und Schriften/ Deutsche Akademie der Wissenschaften zu Berlin; H 37)
Mitscherlich, E. A.: Das Gesetz vom abnehmenden Bodenertrag und was darunter zu verstehen ist. – Berlin, 1952. – (Vorträge und Schriften / Deutsche Akademie der Wissenschaften zu Berlin; H 43)
Mitscherlich, E. A.: Erkenntnisse bei der Pflanzendüngung. – Berlin, 1952. –(Vorträge und Schriften / Deutsche Akademie der Wissenschaften zu Berlin; H 44)
Sauerlandt, W.: Eilhard Alfred Mitscherlich – Ein Forscherleben für die Landwirtschaft. –In: Landwirtschaftliche Forschung. – 9(1956)2. – S. 75-89
Stubbe, H.: Nachruf auf Eilhard Alfred Mitscherlich. – In: Jahrbuch der Deutschen Akademie der Wissenschaften zu Berlin 1956. – Berlin, 1957. S. 497-511