Abstract: In this paper,the experimental study of regulated deficit irrigation (RDI) of potato at different growth stages was carried out at Yimin Irrigation Experimental Station in Minle County in Hexi Oasis Region in 2016. The soil nutrient and soil water and heat in the different growth stages dynamics,growth dynamics,yield effects and water use efficiency were measured. The results showed that the water deficit of potato under drip irrigation was uniform and the utilization rate was high,which was beneficial to the full absorption and utilization of soil nutrient. The soil nutrient was the core of soil fertility and plant was indispensable in the growth and development.Regulated deficit irrigation under plastic film drip irrigation could effectively reduce the loss of soil available nutrients and improved the utilization efficiency of soil available nutrients.The water consumption of potato in different growing stages was affected by the degree of water deficit and the amount of water consumption decreased significantly with the increase of water deficit. The water consumption of potato during the whole growth period with regulation of water deficit was lower than that of full irrigation.It was found that the water use efficiency, irrigation water use efficiency and biomass of the potato were the highest during the tuber formation withslightly water-deficient (WD1), which was 29.04%, 33.22% and 6.59% higher than that of full irrigation all the time (CK control) significantly. Therefore,the mild water deficit irrigation in the tuber formation stage could keep the soil in the potato root area moist all the time,effectively reduce the leakage loss and the evaporation loss between the plants,improve the soil water,fertilizer and heat status,and improve the crop water use efficiency,without significantly reducing the final yield of potatoes.

Key words: Potato, Yield, Regulated deficit irrigation, Soil nutrients, Water use

CLC Number: 

• S152.7

• S158.2

• S275.6