Effects of different crop rotations on yield and yield components of wheat in cold regions of Iran

ABSTRACT: There is a potential to use crop rotation as a tool to maintain the sustainability of agricultural systems. In order to evaluate the effects of different crop rotations on grain and biological yield and yield components of wheat, field experiments were carried out at Agricultural Research Station of Rokh, Iran, during five growing seasons 2006-2010. Crop rotations included wheat-wheat-wheat-rapeseed-wheat (WWWRW), wheat-sugar beet-wheat-sugar beet-wheat (WSWSW), wheat-potato-wheat-potato-wheat (WPWPW), wheat-potato-wheat-rapeseed wheat (WPWRW), wheat-sugar beet-wheat-potato-wheat (WSWPW), wheat-maize-wheat-potato-wheat (WMWPW), wheat-maize-wheat-sugar beet-wheat (WMWSW) and wheat monoculture for the whole period (WWWWW). Plant samples were taken to measure the economic and biological yield and yield components at the end of the study period. Results showed that the effect of different crop rotations had significant (p?0.05) effects on economic and biological yield, yield components and growth characteristics of wheat. The highest economic and biological yields of wheat were observed for WWWRW, with 7855 and 18390 kg.ha-1, respectively, and the lowest was for wheat monoculture, with 5754 and 15790 kg.ha-1, respectively. It seems that the crop rotation with rapeseed the yield and components yield of wheat due to decreasing weeds, disease and pests.