Course: SLF 150 Pasture Management

Reading & Audio Visual

History of Legumes
History of Legumes

For thousands of years farmers were aware that plants belonging to the legume family, such as peas, soy beans and clovers promoted crop growth when planted with other non-legumes such as wheat. Growing a legume crop in a field could also result in the next year's crop of non-legume plants giving a far greater yield. This led to the practice of crop rotation, a practice which can be traced back to techniques recorded in Roman literature.

While the ancient Romans were aware of the improved results gained through crop rotation, they did not know that these benefits were brought about through the replenishment of nitrogen in the soil. A key benefit of crop rotation is the introduction of nitrogen into the soil.

Although farmers have used this technique for millennia, it wasn't until the 19th century scientists determined how this fertilization occurred. Hermann Hellriegel (1831-1895), a noted German agricultural chemist, discovered that leguminous plants took atmospheric nitrogen and replenished the ammonium in the soil through the process now known as nitrogen fixation. He found that the nodules on the roots of legumes are the location where nitrogen fixation takes place.

Nitrogen fixation occurs in root nodules of plants belonging to the legume family.