Residual Effects of Fall- and Spring-applied Nitrogen Fertilizers on Crop Yields in the Southeastern United States

Download or read book Residual Effects of Fall- and Spring-applied Nitrogen Fertilizers on Crop Yields in the Southeastern United States written by Robert W. Pearson and published by . This book was released on 1961 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrogen fertilizer broadcast in November or December on widely different soils at seven locations in Alabama, Georgia, and Mississippi during 1955-59 was only 49 percent as effective as nitrogen fertilizer applied the following spring when measured by corn yields. In terms of nitrogen recovered, the relative effectiveness was 62 percent. There were no consistent differences among the five nitrogen sources applied in the fall as measured by corn yields, but nitrogen recovery tended to be lower from urea than from the other sources. Considerable residual effects of spring-applied nitrogen were found over a period of 16 months based on both yield and nitrogen uptake by the crops. Average uptakes of 25 and 34 pounds per acre of additional nitrogen were made by the second and third crops, respectively, from the 200-pound original application. This residual nitrogen produced average yield increases of 1,600 pounds of dry forage and 19 bushels of corn per acre. These results emphasize the economic importance of residual nitrogen and the need for soil test procedures for its estimation.