The objective of these experiments was to verify the effect of irrigation management and plant population on grain yield of soybean sown after recommends period. The experiment was conducted from January to May 2005 at Federal University of Santa Maria. The experiment design was randomized blocks with subdivided bits in fourth repetitions. In the main bits were distributed three irrigation management: 1) no irrigated; 2) irrigated all cycle; and 3) irrigated in critical periods. In subplot were distributed both plants populations (250.000 and 400.000 plants ha-1). For the irrigated plants ll cycle or only in critical periods, the grain yield did not differ between tried populations. The grain yield of no irrigated plants had an increment of 21% with the increase of plant population to 400.000 plants ha-1.
irrigation; grain yield; Glycine max (L.) Merrill
