# this is the "joy" of such a person's behavior

"this is all the joy they will receive from their godless actions". Bildad is speaking with irony to express that there is not any real joy for the godless person.

# other plants will sprout out of the same soil in his place

"when one wicked man dies, another will take his place".

# sprout

"grow"

# the same soil

"the garden"

# in his place

"in the place of the godless man"