input months pots $ irrigation grain $ nitrogen $ R2D;
%missing(filename=file1, var=R2D, factor_list=months pots irrigation grain nitrogen, missing=( ) );
PROC MIXED;
CLASS months pots irrigation grain nitrogen ;
MODEL R2D = grain|nitrogen|months / DDFM=KR outp=file100;
Random irrigation ;
REPEATED months/ TYPE=CS
SUBJECT=pots;
lsmeans grain nitrogen grain*nitrogen / pdiff;
ods output lsmeans=lsmeans diffs=diffs ;
RUN;