A  field  experiment  was  conducted  to  investigate  the performance  of  soybean  (c.v.  Americana)  when established with zero tillage technique on Imperata dominated area. Four different techniques of alang-alang control  i.e.  imazapyr  (20  kg  ai/ha),  glyphosate  (25  kg  ai/ha),  glufosinate  (3.0  kg  ai/ha)  and  manual cultivation were arranged factorially with time of plantings i.e. 1,2 and 3 months after treatments. 
The  alang-alang  damages  varied  with  herbicides  and  times,  imazapyr  (20  kg  ai/ha) showed slow appearance of damage at 3 months after application it was only 69%, while that of glufosinate was already down to 48% due to regrowth. 
No phytotoxicity was recorded, but the yield was low.