Cyril G.Hopkins

The Story of the Soil; from the Basis of Absolute Science and Real Life

The Farm That Won't Wear Out

The Farm That Won't Wear Out

Nitrogen Bacteria and Legumes

University of Illinois Agricultural Experiment Station Bulletin No. 94: Nitrogen Bacteria and Legumes With special reference to red clover, cowpeas, soy beans, alfalfa, and sweet clover, on Illinois soils

Nitrogen Bacteria and Legumes