Effects of Subsoiling and Tillage Methods on Soil Physical Properties and Sunflower Yield

This study was carried out to investigate the effect of using subsoiler and tillage methods on some soil properties and grain yield of sunflower in Isfahan Kabutarabad Research Station (25 km southeast). The experiment was arranged as a randomized complete block design with 3 replications، including: T1= using moldboard plow in depth of 20-25 cm and flat planting، T2= using moldboard plow in depth of 20-25 cm and furrow planting، T3= subsoiling in depth of 40-45 cm، using moldboard plow in depth of 20-25 cm and flat planting، T4= strip tillage and flat planting، T5= strip tillage، subsoiling and flat planting and T6= strip tillage، furrowing and planting into it. Cone index، bulk density، infiltration rate، root length، plant height، stem diameter، sunflower head diameter، seed yield، thousand seed weight، plant dry weight and oil content were measured. The results indicated that there was no significant difference in bulk density. Also، there was no significant difference in cone index، except at 30 cm depth; however، infiltration rate was greater in subsoiling tillage than in conventional tillage. The results showed that stem diameter in T6 was significantly higher than the other treatments. The subsoiling with high cost did not affected sunflower yield and water use efficiency، therefore، it is not recommended for Kabutarabad area. If strip tillage equipment is available، this method of tillage can be recommended to use.