The source command above is for "C" shell. If you use ksh "Korn shell " try . $HOME/.profile in the top of all your croned scripts remembering to use an if statement to bypass any tty settings like your prompt of the type of terminal you are using...
e.g.
export ORACLE_SID=SID
ORAENV_ASK='NO';. oraenv;ORAENV_ASK='' # The oraenv script provided by Oracle during install!
# this works for ksh c shell syntax is different........
tty -s
if [[ $? -eq 0 ]]
then
# default term type what ever emulator.....
case $TERM in
70092|70094|hp*) export ORACLE_TERM=hp;;
dtt*) export ORACLE_TERM=vt220;tset;;
vt4*|VT4*) export ORACLE_TERM=vt220;export TERM=vt220;stty erase ^?;tset;;
vt3*|VT3*) export ORACLE_TERM=vt220;export TERM=vt220;stty erase ^?;tset;;
vt2*|VT2*) export ORACLE_TERM=vt220;export TERM=vt220;stty erase ^?;tset;;
vt1*|VT1*) export ORACLE_TERM=vt220;export TERM=vt220;stty erase ^?;tset;;
*) export ORACLE_TERM=$TERM;;
esac
export PS1="`hostname | cut -c 1-8` `whoami | cut -c 1-8` > "
fi