Fertilization or fertilizer application is the supplemental application of plant nutrients to crop plants to augment the supply from natural sources. This consists of applying nutrient-containing materials, called fertilizers, generally into the soil in proximity to receptor plants. However, some are added to water, or to air, or applied as foliar spray.
The first artificially produced fertilizer may be the "philosophic dung" or "fattening salt," a substitute to manure (dung) which Johann Glauber (1604-1668) invented. It was prepared from wood ash, lime from burned stone, and well-decomposed organic matter. He wouldn’t know then, but aside from lime, it also added NPK to the soil (Brown 1943, cited by Korcak 1991).
In 1659, ammonium nitrate was discovered in Germany and, in 1773, the urea. In 1809, the Chile saltpetre deposit (sodium nitrate) was discovered. However, it seems that the first time that an intellectual property was acquired was in 1842 by John Lawes of England for the production of single superphosphate. Still, despite the availability of fertilizers, the rate of growth on fertilizer application was slow (Soh 2006).
Going further back before the advent of manufactured or chemical fertilizers, the importance of fertilizer application was already known. Korcak (1991) cited that the Chinese were already aware of the beneficial use of green manure during the Chou dynasty in about 100 BC.
Research did it. According to Went and the Editors of Life (1963), it is research that is mainly responsible for the Agriculture Revolution. The finding that nutrient removal from the soil is a natural consequence of intensive cropping is considered as the most important milestone of research that contributed dramatically to agricultural development.
Julius von Liebeg (1803-1873), a German chemist, made enlightening revelations about plant nutrition and practically boosted the practice of fertilizer application or fertilization. He would become one of the most influential personalities in revolutionizing agriculture throughout the world which means increased productivity manyfold. The following extract from his work (Dedication; Liebeg 1840) is reflective of his precise foresight toward this goal:
“Perfect Agriculture is the true foundation of all trade and industry, — it is the foundation of the riches of states. But a rational system of Agriculture cannot be formed without the application of scientific principles; for such a system must be based on an exact acquaintance with the means of nutrition of vegetables, and with the influence of soils and action of manure upon them.”
Then a Professor of Chemistry in the University of Giessen of Germany (now also called Julius Liebeg University) and a respected authority in Europe, he was commissioned and, on September 1, 1840, presented his report on the state of organic chemistry to the British Association for the Advancement of Science. Soon thereafter on November 30, 1840, he was awarded one of the Copley Medals by the Royal Society (Liebeg 1840).
In the First Part of said report entitled Chemistry in its Application to Agriculture and Physiology, he clearly elucidated the subject of crop removal and its consequence on agriculture. Here’s a portion of the report from the Third American Edition by John W. Webster, 1842:
“... there cannot be the smallest doubt that a soil must gradually lose those of its constituents which are removed in the seeds, roots, and leaves of the plants raised upon it. The fertility of a soil cannot remain unimpaired, unless we replace in it all those substances of which it has been thus deprived."
Now this is effected by manure.”
Apparently the term manuring was meant to refer to fertilizer application. “Manure” from natural sources were used then and in the long past such as animal excrements, ashes, and bones.
According to Liebeg:
“It must be admitted as a principle of agriculture, that those substances which have been removed from a soil must be completely restored to it, and whether this restoration be effected by means of excrements, ashes, or bones, is in a great measure a matter of indifference. A time will come when fields will be manured with a solution of glass (silicate of potash), with the ashes of burnt straw, and with salts of phosphoric acid, prepared in chemical manufactories, exactly as at present medicines are given for fever and goitre.”
Further, Liebeg popularized the Law of the Minimum. It explains that crop yield is limited by the essential element having the shortest supply in the soil. Therefore, supplying that limiting element will lead to improved crop productivity and the law of the minimum will shift to another element. It seems, however, that it was Carl Sprengel (1787-1859) who first discovered the law of the minimum (soils.wisc.edu 2000).
The Law of the Minimum, or principle of limiting factors, along with the finding that crop plants remove some mineral nutrients from the soil, became the basis of the modern practice of fertilizer application. Large amounts of chemical or synthetic fertilizers are now used worldwide and NPK (for nitrogen, phosphorus and potassium) has become a byword in crop agriculture.
According to Soh (2006), in 1998 the volume of fertilizers used around the world reached about 360 million tons. These were applied over an area of about 1.4 billion hectares or at an average of about 257.1 kg per hectare. FAO (2011) likewise presents data showing annual growth rate of 1.7%, 1.9%, and 3.1% in the world demand for nitrogen, phosphate and potash, respectively, from 2011 to 2015.
Based on research studies, it has long been established that fertilization requires knowing the nutrient needs of crops and the amounts of nutrients that the soil can supply. Consequently, the so called Fertilizer Bill of Rights has become the guiding rule in fertilizer application: Right Kind, Right Amount, Right Time, Right Place (Thorup 1984).
REFERENCES[FAO] FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS. 2011. Current world fertilizer trends and outlook to 2015. Retrieved Jan. 5, 2013 from ftp://ftp.fao.org/ag/agp/docs/cwfto15.pdf.
SOILS.WISC.EDU. 2000. Essential elements for plant growth: law of the minimum. Retrieved Nov. 15, 2012 from http://www.soils.wisc.edu/~barak/soilscience326/lawofmin.htm.
THORUP RM (ed.). 1984. Ortho Agronomy Handbook: A Practical Guide to Soil Fertility and Fertilizer Use. San Francisco, CA: Chevron Chemical Company. 454 p.
WENT FW, THE EDITORS OF LIFE. 1963. The Plants. New York: Time Incorporated. 194 p.
(Ben G. Bareja, Jan. 2013)