effect of subsoiling and irrigation periods upon corn yield

subsoil compaction, may occur naturally or a consequence of machinery traffic, causes reduction in crop yield. the aim of this work was to characterize the effects of subsoiling and irrigation on yield of corn. this study was conducted on the silty loam soils of miyandoab agricultural research station on the base of split plots design with 12 treatments and 4 replicates during the 1999 and 2000 years. irrigation treatments were applied in main plots and consisted of 11, 14, 17, and 21 days irrigation interval, and subsoiling treatments were applied in the sub plots and consisted of 45 and 55 cm depth subsoiling and no subsoiling. the corn yield in 11, 14, 17, and 21 days irrigation interval were 13, 12.09, 11 and 9.45 t/ha and subsoiling treatments and no-subsoiling were 11.4, 11.3 and 10.6 t/ha respectively. the irrigation and subsoiling had significant effect on corn yield. the highest yield (13 t/ha) among the irrigation treatment was 11-day irrigation interval, and in subsoiling treatments, yield of 11.3 and 11.4 t/ha was determined respectively.