Date of this Version
Thesis (M.S.)--University of Nebraska--Lincoln, 1958. Department of Agronomy.
An experiment was initiated at Agronomy Farm Lincoln, Nebraska in 1946 to study the influence of cropping systems and nitrogen fertilization on the maintenance of nitrogen and organic matter in Sharpsburg silty clay loam soil.
The cropping systems included alfalfa, bromegrass with and without an application of nitrogen fertilizer, an alfalfa-bromegrass mixture, sweetclover, and a corn, oats, wheat rotation with and without applications of nitrogen fertilizer. These cropping systems were followed for a six year period from 1946 to 1951. Thereafter, the plots were split crosswise and cropped to corn, oats and wheat with nitrogen fertilizer applied to one subplot with no nitrogen being applied to the other subplot. Soil samples were taken in 1946, 1949, 1952 and 1957 to evaluate changes in soil nitrogen and carbon. Laboratory analyses included total nitrogen, oxidizable carbon, nitrification rate, soil reaction, and available phosphorus.
Advisor: Leon Chesnin.