The Effects of Subsoiling on Soil Physical Properties and Sunflower Yield in Mahiar Area, Isfahan

This study was carried out to investigate the effect of using subsoiler for conventional tillage on some soil properties and sunflower yield. The research was carried out in Mahyar Region (30km South) in 2002. The experiments were performed using complete randomized block design with three replications. The treatment comprised 1) conventional tillage at depth of 20-25 cm + flat planting (T1), 2) conventional tillage at depth of 20-25 cm + furrow planting (T2) and 3- sub soiling at depth of 40-45 cm + conventional tillage in depth of 20-25 cm + flat planting (T3). The cone index, bulk density, infiltration rate, root length, seed yield, plant dry weight and oil content were measured. The results indicated that there was no significant treatment difference in the bulk density and infiltration rate. The cone index was smaller in T2 and T3 in 10-20 and at 20-30 cm of depth. The results showed that the oil content in T2 was significantly lower than other treatments. The subsoiling with high cost did not affect the sunflower yield so that it is not recommended to use.