A species of alfalfa called falcata has been found to thrive on the Northern Plains, where other US-grown varieties fizzle out, reports the Agricultural Research Service.The seeds of the high-protein yellow-flowering subspecies of the Medicago sativa alfalfa originally came from the Siberian plains.
ARS soil scientist Gerald Schuman, with the RRRU's High Plains Grasslands Research Station, have been working with a rancher who owns 1,500 acres of falcata on land that originally received the seeds nearly 100 years ago.
On the land with falcata, Schuman and colleagues have found a large increase in forage production - at times nearly double - compared with rangelands not interseeded with falcata.
The scientists report that part of the reason for falcata's success is that alfalfa - a legume - brings with it friendly bacteria, called rhizobia, which thrive in nodules on the plant's roots. Rhizobia turn atmospheric nitrogen into a form that plants can use to promote their own growth. Schuman found that soil where falcata had been interseeded for at least three years had large increases in nitrogen.
The team also found evidence that falcata could lower levels of atmospheric carbon dioxide. They saw increases in soil carbon of more than five tons per acre on some falcata-interseeded rangeland, when compared with non-interseeded areas.
ARS is the US Department of Agriculture's chief scientific research agency.