the effect of cover crop and different tillage systems on soil physical properties and yield of potato

background and objectives: suitable tillage methods and planting cover crops are such factors in sustainable agricultural systems, which play an important role in the sustainability of agricultural production systems. minimum and no-tillage systems methods that leave instead of usually more than 30 percent of crop residue on the soil surface, are used to reduce soil erosion, improve soil physical and biological characteristics, improve use efficiency and increase water infiltration (10 and 15). crops residues have many benefits towards sustainable production practices, especially in conservation tillage systems (35). the benefits cover crop can be referred improvement of soil physical and chemical properties, maintain soil moisture, increase of soil organic matter, adjustment soil temperature, increase biodiversity and finally increasing of crop yields (14 and 37). this study was conducted to evaluate the effects of different tillage systems and cover crops types on soil properties, yield and yield components of potato, at the agricultural research station faculty, of bu-ali sina university, during growing season of 2013. materials and methods: the experiment was conducted as split-plot based on a randomized complete block design with three replications. the main factor consisted three tillage systems (conventional tillage, minimum tillage and no-tillage) and three levels of cover crop (vetch, barley and without cover crop) as subplot. results: barley cover crop returned to the soil more dry matter than vetch, so that the barley biomass 1.21 times the of vetch biomass. the results showed that most soil organic matter (1.32 percent) was obtained in the no-tillage system with vetch cover crop. no tillage and minimum tillage treatments by mean of 11.75 percent of soil moisture caused the highest soil moisture. cover crops increased soil moisture up to 6.26 percent in compared to control. the highest number of stems per plant and plant height were obtained by conventional tillage system. number of stems per plant, plant height, maximum leaf area index in vetch cover crop treatments were 24.76, 17.58 and 37.79% more than control, respectively. the maximum number of tubers (48.15 tuber per square meters) was obtained in conventional tillage system. planting cover crops increased number of tubers to 28.79 percent in compared with the control. the maximum tuber yield was observed in conventional tillage system with cover crops vetch and barley by 48.68 and 47.95 ton per hectare, respectively. conclusion: it can be deduced cover crop improvement of soil organic matter, maintain of soil moisture and increased tuber yield of potato, especially under minimum and no-tillage systems.