Atoms in Agriculture The Understanding the Atom Series Nuclear energy is playing a vital role in the life of every man, woman, and child in the United States today. In the years ahead it will affect increasingly all the peoples of the earth. It is essential that all Americans gain an understanding of this vital force if they are to discharge thoughtfully their responsibilities as citizens and if they are to realize fully the myriad benefits that nuclear energy offers them. The United States Atomic Energy Commission provides this booklet to help you achieve such understanding. [Illustration: ] Edward J. Brunenkant, Director Division of Technical Information UNITED STATES ATOMIC ENERGY COMMISSION Dr. Glenn T. Seaborg, Chairman James T. Ramey Wilfrid E. Johnson Dr. Theos J. Thompson Dr. Clarence E. Larson Atoms in Agriculture by Thomas S. Osborne CONTENTS RESEARCH IN THE UNITED STATES 1 HOW ARE RADIOISOTOPES USED IN RESEARCH? 2 They May be Used as “Tracers” 2 How Effective Are Radioactive Tracers? 3 PLANT NUTRITION AND METABOLISM 4 What Happens to Fertilizer in the Soil? 4 Do Plants Absorb Through Roots Only? 4 Where Should Fertilizer be Placed? 5 Do Fertilizers Move Fast in Plants? 5 What Else Do Radioisotopes Tell Us? 5 PLANT DISEASES AND WEEDS 8 How Can We Combat Plant Diseases? 8 Why Do Chemicals Destroy Some Plants? 10 ANIMAL NUTRITION AND METABOLISM 11 How Nutritious Are Various Feedstuffs? 11 Can Lean Meat be Estimated “on the Hoof”? 12 Does Thyroid Affect Milk—Egg Production? 13 More Tracers in Animal Nutrition Research 13 INSECTS 15 Where and How Fast Do Insects Travel? 15 How Far Do Insects Carry Pollen? 15 Are Predators Used to Destroy Insects? 16 Can Tracers Measure Spray Residues? 17 RADIOISOTOPES AS RADIATION SOURCES 17 Can Radiation Produce New Plants? 18 Can Radiation Destroy Germs and Insects? 19