Application of {HEAD ~ outside forces}, such as caused by tilling, rainstorms, {TAIL ~ irrigation}, etc., insures complete breakdown of these granules 
such as caused by
Application of { HEAD ~ outside forces } , such as caused by tilling , rainstorms , { TAIL ~ irrigation } , etc . , insures complete breakdown of these granules
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH