Abstract: 【Objective】Intercropping is one of the main technologies to solve the potato continuous cropping obstacles, and increase crop productivity. However, it is very important to consider the local soil water capacity before developing a potato intercropping system in the semiarid area.【Method】A 4-year field experiment was carried out from 2011 to 2014 with four treatments: (1) mono-potato (PM), (2) potato and faba bean intercropping (PF), (3) potato and soybean intercropping (PS), and (4) potato and haricot bean intercropping (PH). The soil temperature, soil water content and crop yield had been investigated; the crop water consumption, economic returns and water economic yield were calculated, to understand the effects of different intercropping models on crop productivity and soil moisture. In addition, soil water sustainability was appraised under intercropping system on semiarid area. 【Result】The intercropping relieved the heat stress from June to July, the soil temperature in 0-25 cm profile of PF, PS and PH decreased by 0.8-3.6℃, 0.4-2.8℃ and 0.8-1.8℃ from 2012 to 2014 respectively, as compared with PM, this may advantage to the potato growth. The soil water content decreased, especially, the deeper soil water depleted in intercropping treatments as compared with mono-potato treatment, the depth of soil water depletion reached to 200 cm in the intercropping treatment, compared with PM, the soil water depletion of PF increased by 41.6-131.7 mm in potato pre-flowering period, and decreased by 48.6 mm and 34.3 mm in dry year (2011) and normal year (2012) in post-flowering period respectively. Although the soil water depletion of PH treatment increased in pre-flowering period, but not decreased in post-flowering period significantly, as compared with PM. The variation of soil water depletion in pre- and post-flowering period in PS was between PF and PH. The economic returns and water economic yield of PH was highest, increased by 29.8%-51.4% and 19.8%-24.0% than PM, respectively. The soil water storage in 0-200 cm profile increased more than 100 mm through the 4 experimental years, indicated that there were no adverse effect on soil water sustainability in potato and beans intercropping, when the whole field plastics mulching and ridge-furrow planting technology used in semiarid area. 【Conclusion】Potato and haricot bean intercropping decreased the soil temperature in the hot season (i.e. June and July), increased potato water consumption in post-flowering period, resulted in significant increment of incomes, and had no risk on the annual soil water balance, which could be widely applied in the rain-fed semi-arid area of northwest Loess Plateau.

Key words: semi-arid area, whole field plastics mulching and ridge-furrow planting, potato, beans, intercropping, soil thermal- moisture status, income