00506naa a2200181 a 450000100080000000500110000800800410001910000180006024501010007826000090017965000100018865000160019865000250021465000090023965000100024870000200025877300460027816135511995-06-27       1990    bl uuuu     u00u1 u    #d1 aVARVEL, G. E.  aResidual soil nitrogen as affected by continuons, two-year, and four-year crop rotation systems.  c1990  aMilho  aNitrogênio  aRotação de Cultura  aSoja  aSorgo1 aPETERSON, T. A.  tAgron. J.gv. 82, n. 9, p. 958-962, 1990.