ConTeXt defaults to inserting a \blank
before every footnote placement; you can disable this by setting the before
key of \setupfootnotes
to something empty:
(skip past the irrelevant setup code to the demonstration at the end)
%%% Begin irrelevant setup code
\setuppapersize[A7, landscape][A4, portrait]
\setuppaper[nx=2,ny=4]
\setuparranging[XY]
\setuppagenumbering[state=stop]
\setupindenting[3em, yes]
\setupbodyfont[11pt]
\startsetups[*default]
\directsetup{*reset}
\clubpenalty=0
\widowpenalty=0
\parskip=0pt plus 1fil
\stopsetups
\define[1]\samples{
\noindent\bold{#1:}
\dorecurse{4}{
\dorecurse{20}{
\convertnumber{words}{\recurselevel}
}
\footnote{footnote}
\par
}
\vfill
\page
}
\setupbackgrounds[text][
frame=on,
framecolor=lightgray,
]
\setupfootnotes[
topframe=on,
framecolor=lightgray,
]
%%% End irrelevant setup code
%%% Demonstration:
\starttext
\samples{Default}
\setupfootnotes[
before={},
]
\samples{No space}
\setupfootnotes[
before={},
rule=off,
]
\samples{No space, no rule}
\setupfootnotes[
before={\blank[2*line]},
rule=normal,
]
\samples{Extra space}
\stoptext