Abstract: The effect of rotation and intercropping on soil temperature for potato in north Yinshan mountain was investigated in 2009.The main treatments were rotations (potato rotation,P-M and P-R,and potato continuous cropping,P+M and P+R)two sub treatments intercrops (potato/millet,P/M;potato/rape,P/R).Soil temperature at 10cm soil layer was measured continuously by Heki temperature sensors.The results showed that soil temperature was a sine curve with the minimum value occurred at 6：30 to 9：00 and the maximum occurred at 16：30 to 18：00.The minimum and maximum soil temperature occurred earlier 0.5-1.5 hours in rotation system than that in continuous cropping system,and the diurnal range was higher 0.6-3.5℃.Effect of planting system on soil temperature was different in different growth stages.In seeding and tuber initiation stage the daily mean and accumulation soil temperature in rotation were higher than in continuous system as influenced by different previous crops,which was no significant difference between intercropping with two crops.In tuber swelling and starch accumulating stage the soil temperature of P-R was lowest and that of P-M was highest as influenced by the height and growth vigor of intercropping crops.There was significant correlation among the potato yield and diurnal range of whole stages,mean and maximum temperature of early stage and minimum temperature of late stage.Therefore,the rotation system increased potato yield as it increased mainly the soil temperature in seeding stage and diurnal range of whole stages.The high temperature damage would be avoided by intercropping with rape for its higher plant,while the more quantity of heat would be absorbed and reached more yield if the potato were intercropped with millet.

Key words: Rotation, Intercropping, Soil temperature, Potato