EFFECTS OF MANURES, AMMONIUM NITRATE AND S-COATED UREA ON YIELD AND UPTAKE OF N BY CORN AND ON SUBSEQUENT INORGANIC N LEVELS IN SOILS IN SOUTHERN QUEBEC

Abstract

Effects of added N in the form of ammonium nitrate, S-coated urea, solid cow manure, liquid hog manure, and liquid hog manure plus straw on yield and N uptake of corn (Zea mays L.) were determined in 1971. Residual effects of the fertilizers were measured in 1972. Levels of added N were 150 kg/ha, on three soils varying in texture. In 1971, highest yield and N uptake was found using ammonium nitrate, followed by S-coated urea. The manures were not different than the control, and the average values with liquid manure plus straw were generally lowest. Ammonium nitrate treatments had the lowest mineral N levels in the soil profile in September. Thus, ammonium nitrate was considered to have the lowest pollution potential, assuming that fall-accumulated inorganic soil N was a hazard for pollution of groundwater.