Agrochemistry
The agrochemicals (including agricultural chemicals, agricultural chemistry ) is a research and development branch of chemistry and the same time a large-scale industrial production area . It deals with animal health, pest control, crop protection and fertilization, harmful plant reduction and the chemical processes in soils used for agriculture and forestry ( soil chemistry ) to improve soil fertility .
The common doctrine is that without agrochemical products such as fertilizers and pesticides, the production of crops and cereals with a growing world population , shrinking arable land and increased demand for biofuels would not be able to meet global demand.
history
Ever since the beginning of plant cultivation, humans have been looking for methods to improve plant growth and to protect the seeds and the harvest from damage with the aim of increasing the yield and quality of the harvest and ensuring that the population is fed. In ancient times, man began to use chemical methods, especially fertilization . The Babylonians used organic fertilizers such as manure or liquid manure as well as vegetable products such as compost , the Egyptians used the Nile mud left behind by floods as mineral fertilizer. Homer mentioned the use of cow dung as fertilizer in the Odyssey around 800 BC . Pliny the Elder reported on the use of a calcareous marl as an inorganic mineral fertilizer by the Ubier and on green manure , in which the Romans plowed in legumes such as field beans to improve the soil .
"The soil on which field beans are grown is as happy as if it had received fertilization."
In the Middle Ages, at the end of the first millennium, people in Central Europe used wood ash fertilizer as a source of potassium (see also terra preta ).
In addition to sufficient plant nutrition, the destruction of the crop by insects and fungal attack was a serious problem. In ancient times, farmers used sulfur and arsenic suspended in oil as insecticides . Around 1637, people began to develop methods against fungal attack on grain seeds ( pickling ). Based on the discovery that seeds reclaimed from the sea were free from fungus, they developed a method of treating seeds with salt water and lime . In 1755 Mathieu Tillet (1714–1791) described in his work Dissertation sur la cause qui corrompt et noircit les grains de blé dans les épis; et sur les moyens de prévenir ces accidents the treatment of wheat seeds with lime and salt against the mushrooms Tilletia tritici and Tilletia laevis later named after him by Charles and Louis Tulasne .
In 1798, the economist and demographer Thomas Robert Malthus developed the thesis that food production could only increase arithmetically while the world population would grow geometrically. Accordingly, a point in time would arise from which the harvest yields would no longer be sufficient to feed the entire population of the world. Around the same time, Alexander von Humboldt recommended the use of guano and Thaddäus Haenke recommended the use of Chiles nitrate for fertilization.
Carl Sprengel carried out the first systematic investigations into agrochemistry from 1828 onwards, inspired by his work as a student of Thaer in Möglin, the father of rational agriculture, Albrecht Daniel Thaer . He founded the mineral theory "... because it cannot be denied that if a plant needs 12 substances for its formation, it will never arise if only one is missing in this number, and it will always grow poorly if one of them is not present in such an amount as the nature of the plant requires ". Carl Sprengel became the founder of mineral fertilization. Based on his scientific work, companies were founded mainly in England and Germany that produced mineral fertilizers. Superphosphate was produced in England in 1846 and in Germany from 1855. Furthermore, large amounts of saltpetre from Chile and guano from Peru were imported. Shortly thereafter, it was recognized that ammonium sulfate , a by-product of the coking plant , was suitable as a nitrogen fertilizer . With the development of the Haber-Bosch process in 1909, for which Fritz Haber and Carl Bosch were awarded the Nobel Prize in Chemistry , nitrogen fertilizers became available on a large scale. In addition to the important mineral fertilizer components such as nitrogen (as ammonium , nitrate or amide nitrogen ), phosphorus and potassium, the importance of trace elements such as zinc , boron , manganese , copper and molybdenum was soon discovered.
From the middle of the 18th century onwards, weeds were partly combated with salts such as iron sulphate , copper sulphate and sulfuric acid , later also sodium chlorate and dinitro- ortho- cresol . Until the development of the herbicide 2,4-dichlorophenoxyacetic acid , however, weeds were mostly removed by mechanical processing. From 1945 onwards, a number of herbicidal active ingredients such as carbamates , triazines , sulfonylureas and amino acid derivatives were developed .
Pests such as Phytophthora infestans destroyed the entire potato harvest in Ireland several times in the 1840s, resulting in a famine with many deaths. Events like this led to intensive research in the field of agrochemistry.
application
Various groups of chemicals are used as active ingredients. In addition to purely organic substances such as amides , anilides , carbamates, pyrethroids or benzimidazoles , organic tin and phosphorus compounds , mineral oils and many other substances are also used. The formulation poses a challenge . Ready-to-use agrochemicals often consist of a mixture of several active ingredients as well as emulsifiers, stabilizers and other non-active ingredient components that make it possible to use an active ingredient as a plant protection agent .
Main products are like:
as well as mineral fertilizers .
Leading large companies in the branch are in the process of supplementing agrochemistry with biotechnology and the use of genetically modified plants .
Multinational agrochemical companies include BASF Crop Protection, Bayer , Corteva , FMC , and the ChemChina subsidiaries Adama and Syngenta .
Agrochemistry and Ecology
The agrochemical industry in Central Europe has been criticized for violating ecological and sustainability principles and causing damage to people and nature (e.g. through DDT ) since the late 1980s by promoting industrial agriculture and genetic engineering . Agricultural chemistry in its current form is often viewed as incompatible with sustainability and ecological agriculture , although the targeted and well-dosed use of modern agrochemicals can help to combat crop failures and thus world hunger . In addition, a radical departure from current practices is hardly realistic in the short term, also due to crop failures. The goal, however, must be to develop concepts that avoid damage to people, nature and the environment.
See also
Web links
Individual evidence
- ↑ Jerry Cooper, Hans Dobson: The benefits of pesticides to mankind and the environment . In: Crop Protection . tape 26 , no. 9 , September 2007, p. 1337-1348 , doi : 10.1016 / j.cropro.2007.03.022 .
- ^ W. Luck: Homo investigans: The social scientist . Springer-Verlag, 1976, ISBN 978-3-642-85298-5 , p. 93 ( Google Books ): "It is already estimated that half of the world's population lives from the increased harvests from the synthetic fertilizers of chemists"
- ↑ a b Winnacker-Küchler : Chemical technology, nutrition, health, consumer goods , 5th edition, volume 8, p. 216 ff.
- ↑ a b V. Morton, T. Staub: A Short History of Fungicides ( Memento of the original from April 16, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. .
- ↑ Carl Sprengel and the mineral theory created by him as the foundation of the new plant nutrition theory, Wolfenbüttel 1950, 1st edition, p. 129, keyword: mineral theory.
- ^ Ullmanns Encyklopadie der technischen Chemie, 4th edition, Volume 18, p. 5, keyword: pesticides, toxicology.
- ↑ Jürgen Weber: Sustainability and Controlling . John Wiley & Sons, 2012, ISBN 3-527-50652-7 , pp. 39 ( limited preview in Google Book search).
- ↑ Johannes Friedrich Diehl: Chemistry in food residues, impurities, ingredients and additives . John Wiley & Sons, 2012, ISBN 3-527-66084-4 ( limited preview in Google Book Search).
