| A field experiment was conducted in 2023 to identify suitable cover crops and their optimal sowing periods for potatoes grown in furrows. The experiment included five treatments: sowing Vicia sativa two weeks before potato planting (PV1), sowing Vicia sativa concurrently with potato planting (PV2), sowing hairy vetch two weeks before potato planting (PM1), sowing hairy vetch concurrently with potato planting (PM2), and a potato monoculture as the control (P). The study examined the effects of different cover crops and sowing periods on soil moisture, water consumption, evapotranspiration, potato yield, and water use efficiency in field conditions. The results indicate that: (1) Each covering treatment increased the soil moisture content of the 0~110 cm soil layer in the field, throughout the growth period especially after potato flowering (after cutting cover crops) to varying degrees compared with the P treatment. The effect of the hairy vetch treatment was better than that of the Vicia sativa treatment. Moreover, PM1 treatment significantly increased the soil moisture storage in the 0~110 cm soil layer during the tuber expansion period, which was 7.78% higher than the P treatment. (2) The covering treatment reduced potatoes’ soil evaporation, E/ET, and water consumption to varying degrees throughout the growth period of potatoes over P treatment. The PM1 treatment had the best effect on reducing soil evaporation and the E/ET during the whole growth period of potatoes, significantly lower than the P treatment by 29.64% and 25.66%, respectively as compared to P treatment. Pre\|potato flowering (the growth period of cover crops), the transpiration of PM1 treatment was significantly higher than P treatment by 9.67%, but there was no significant difference in water consumption between these two treatments. After cutting cover crops, the water consumption of each covering treatment was significantly lower than P treatment by 5.85%~16.64%. (3) The potato yield, commercial potato rate and water use efficiency of PM1 were significantly higher than other treatments by 8.89%~35.95%, 17.10%~49.98%, and 8.87%~43.75%, respectively. Therefore, sowing hairy vetch in furrows and covering it with cuttings two weeks before planting potatoes can ensure adequate water supply during the tuber expansion period, optimize water consumption patterns, improve potato yield and water use efficiency, and promote stable, high yields in the arid agricultural regions of central Gansu. |