Comparison of wheat based rotation systems in Gonbad Kavous region

To study and comparison of different crop rotations based on wheat in regard to yield, economic performance, soil fertility, weed populations, pests and diseases, an experiment was conducted at Agricultural Research Station of Gonbad Kavous during five years (from 2005 to 2010 cropping seasons). The six crop rotation systems consisted of 1. wheat-wheat, 2. wheat-rapeseed, 3. wheat-chickpea, 4. wheatcotton, 5. wheat-watermelon and 6. wheat-sunflower, were evaluated in a randomized complete block design with 3 replications each in 180 m2 plots size. Performed rotation systems were based on prevailing cultivation of the region (wheat cv. Darya). Wheat plants were cultivated in all plots at the start and end of the experiment. Results from analysis of variance revealed that effect of rotation was significant on wheat characteristics including plant height, number of fertile spike per m2, number of seeds per m2, 1000 grain weight, number of fertile spikelets per spike and grain yield. Results of means comparison of treatments showed that highest (5343 kg.ha-1) and lowest (3990 kg.ha-1) wheat grain yield obtained from wheatchickpea and wheat- sunflower rotations, respectively. Based on the results of this experiment, wheatchickpea rotation can be recommended for the studied region.