Effect of Conservation Tillage and Crop Rotation on Dryland Wheat Yield and Weed Population

Dryland winter wheat (Triticum aestivum L.) is a major crop in the west region of Iran. Information is limited on the success of more intensive dryland cropping systems with conservation tillage management. An experiment was conducted to determine the effect of four tillage systems and three crop rotations on weed population and wheat yield on a silty clay loam in Tajarak Research Station (Kaboudarahang Township), Hamedan. This research was conducted in the form of a split plot experimental design with four tillage methods and three crop rotations in three replications. Main plots were three crop rotations including: (R1) fallow –wheat, (T2) wheat – wheat (T3) chickpea- wheat. Four tillage methods including (T1) conventional tillage (moldboard plow + cyclotiller equipped with roller), (T2) combination tiller (chisel plow equipped with roller), (T3) combination tiller (chisel plow equipped with roller) and (T4) dirct drilling were considered as sub plots. During growing season, weed density were measured. At the end of the growing season (harvesting time), wheat yield were measured. Tillage treatments had significant effect on wheat yield but crop rotations had not significant effect on wheat yield. T3 treatment had the higher yield between treatments. Tillage methods and crop rotations had significant effect on weed population.T1 treatment and R2 rotation had lower weed density between treatments.