Clovers – plants that changed the world

Abstract

Red clover and white clover made a slower breakthrough to the group of significant world crops. Clovers were domesticated in 1000 AD in the Maori Andalusia at the south of Spain, and afterwards gradually spread to the other parts of Europe. They served as the main source of atmospheric nitrogen, an important biogenic element in nutrition of cereals and potato, which had an increasing trend in cultivation according to population growth in Europe. During 13th and 14th century, scarce cultivation of nitrogen-fixing plants, such as clovers, accompanied by unsuitable environmental conditions because of the sudden climate change, resulted in the decline in cereal cultivation due to insufficient nitrogen supply of Eurasian soils. It ultimately brought about great famine and high mortality to Eurasian population. Red clover seeds were brought from Holland to England during 1620, spread across the British Isles in the late 17th century, and took on paramount importance in the 17th and 18th century agriculture. The introduction of red clover into the three crop rotation system (in England and then the other European countries) developed into a four crop rotation system, i.e. “The Norfolk four-course system“. Red clover became the national flower of Denmark in 1936, while clover flowers adorn the National Emblem of the Republic of Belarus. At the dawn of 21st century, following the trends of sustainable and organic agriculture, clovers gained back their significance in most EU countries primarily as a valuable component of grass-legume mixtures in the production of good-quality, well-balanced and safe feed, but also for their leading role as a preceding crop in crop rotation, and for improvement of physical and chemical properties of degraded soils.