The Efficiency of Anhydrous Ammonia as a Source of Nitrogen on Fall‐planted Oats for Forage and Grain Production

ALARGE acreage of oats and similar crops which feed heavily on nitrogen is planted for winter grazing in the South each fall. At the present time nitrogen as anhydrous ammonia is the cheapest form available. Anhydrous ammonia costs approximately 4 cents less per pound of nitrogen than the cheapest source of solid nitrogenous fertilizer, ammonium nitrate. The purpose of this investigation was to determine the relative efficiency of anhydrous ammonia as compared with ammonium nitrate for the production of oats for forage in the fall and winter and for grain in the spring. Anhydrous ammonia was first used as a source of nitrogenous fertilizer in irrigation water by Waynick (4) in the early 1930's; however, Shell Chemical Company pioneered its use in irrigation water on an extensive scale. Andrews, et al. (i, 2) began the use of aqua ammonia (NH^OH) as a nitrogenous fertilizer at the Mississippi Agricultural Experiment Station in 1943. In 1944 work was started with anhydrous ammonia applying it directly to the soil with a machine developed by Edwards and Andrews (3). Investigations were carried on" with corn, cotton, and oats. Yield data, from the field experiments indicated that anhydrous ammonia compared favorably with ammonium nitrate as a source of nitrogen for the production of row crops. However, the'results-obtained from field experiments' with oats varied with the time of application and soil reaction. The practical significance of anhydrous ammonia as a cheap-source of nitrogen is emphasized by the fact that approximately 200,000 acres of row crops were fertilized with anhydrous ammonia in Mississippi during 1947.