How it began
Artturi Ilmari Virtanen, born in Helsinki in 1895, studied the chemistry of nutrients and headed the laboratory of the Valio dairy cooperative from 1921. His research from 1925 led to a fodder preservation method that historian Jarmo Pulkkinen dates to 1928; the Nobel Foundation gives 1932, the year it was patented. The method carries his initials, AIV.
How it works
The method acidifies fresh fodder to below pH 4 by adding dilute hydrochloric or sulfuric acid as the green crop is stored. The increased acidity stops the harmful fermentation and breakdown that would otherwise destroy the grass's proteins and vitamins. According to the sources, the acid has no adverse effect on the nutritive value of the fodder or on the animals that eat it.
How it spread
In the early 1930s the AIV method was licensed in more than ten European countries and in the United States. It was used mainly in Scandinavia and the Netherlands, and modified versions were used in Germany and the United States. In Finland it stayed in use in its original form until 1968. The method never transformed fodder growing and cattle feeding in the way Virtanen had expected. Pulkkinen's history of the method says its spread was slowed by scientific, economic, technological and even logistical obstacles.
What changed first
Storing green fodder well matters most where winters are long. With AIV silage, cows could produce more nutritious milk through the year without imported fodder. In 1945 Virtanen received the Nobel Prize in Chemistry "for his research and inventions in agricultural and nutrition chemistry, especially for his fodder preservation method".
