This study was conducted from April 2020 to August 2021 at the Oil Crops Institute of Gansu Academy of Agricultural Sciences (N 35°48?, E 104°49?) experimental base in Dingxi City, Gansu Province, China (Figure 1). The experimental area belongs to a hilly and gully semi-arid area of the Loess Plateau, with an average altitude of 2050 m, an average annual sunshine duration of 2453 h, a frost-free period of 140 d, average annual precipitation of 390 mm, annual evaporation of up to 1500 mm, an average annual temperature of 6.3 °C, an extreme maximum temperature of 34.3 °C, and an extreme minimum temperature of ?27.1 °C. The experimental site is terraced and the soil is loess soil. The total nitrogen content of the plow layer soil is 0.81 g·kg?1, organic matter content is 10.12 g·kg?1, total phosphorus is 0.69 g·kg?1, alkali-hydrolyzed nitrogen is 48.91 mg·kg?1, available phosphorus is 27.43 mg·kg?1, available potassium is 108.30 mg·kg?1, and pH is 8.14.

The total precipitation from sowing to harvest in 2020 and 2021 was 294.3 mm and 182.7 mm, respectively. The effective precipitation days during the growing season accounted for 57.58% (2020) and 52.77% (2021) of the growing season. Read More