%0 Journal Article %A Mayland, H.F. %A McIntosh, T.H. %C London %D 1966 %F nwisrl:461 %J Nature %N 5021 %P 421-422 %T Availability of Biologically Fixed Atmospheric Nitrogen-15 to Higher Plants %U https://eprints.nwisrl.ars.usda.gov/id/eprint/461/ %V 209 %X The direct utilization by higher plants of nitrogen fixed by blue-green algae could play a substantial part in the Earth's nitrogen cycle. That certain species of blue-green algae can fix nitrogen when grown in solution culture is well established. The maintenance of soil nitrogen supplies in rice paddy has been attributed to the growth and fixation of nitrogen by blue-green algae. Recently it was postulated that the blue-green algae may be important in the nitrogen economy of grazing lands.