\defineinterlinespace
  [footnote]
  [line=6ex]

\setupnotation
  [footnote]
  [alternative=serried]

\setupnote
  [footnote]
  [paragraph=yes,
   interlinespace=footnote]

\showframe

\starttext

    \dorecurse{4}{These are footnotes\footnote{\input knuth}. }

\stoptext
