Effects of Continuous Corn (Zea mays L.), Manuring, and Nitrogen Fertilization on Yield and Protein Content of the Grain and on the Soil Nitrogen Content
1973
Anderson, F. N. | Peterson, G. A.
Continuous corn (Zea mays L.) was produced from 1912 to 1972 on an irrigated soil of the Typic Haplustoll group in western Nebraska. Corn yields declined rapidly from 1912 to 1922 when no manure or N fertilizer was used. Annual applications of manure on one-half of the plot area beginning in 1941 increased yields linearly until 1953. Nitrogen fertilization beginning in 1953 increased corn yields 4685 kg/ha above the control during the first year of application on the nonmanured treatment. Maximum yields have been reached with a combination of manure and N fertilization. Total soil N data indicate that manuring from 1941 to 1972 has returned the soil N level to about 90% of the level that was present in the uncultivated soil in 1912.
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