| Gradient “3414” fertilizers and different irrigation amounts were applied in field experiments with drip fertilization conditions on rapeseed at Ershilipu town, Xining city, Qinghai province, to investigate rules of water and fertilizer requirements for spring rapeseed cultivation by drip fertigation technology. The results showed that rapeseed yields reached 2 443.5～3 132.0 kg·hm-2, which was increased by 0.8%～29.2% than those with the control treatment. N, P, and K fertilizer utilization rates were 50.9%, 22.5%, and 56.7% respectively. Water utilization efficiency (WUE) reached over 4.0 kg·hm-2·mm-1, which became increased by 42.1%～61.4% compared with the control. It was further found that level of soil water content during growing period reached lowest at the bud stage, followed by at the blossom stage, and then at the pod stage. At the bud stage, with the increase of soil depth in 0～60 cm layers, the water content went up. At midterm and late stages, water content became increased first then dropped. Minimal values of soil water content at 5 cm away from the dripper were lower than those 15 cm away. In conclusions, the recommended fertilizer amounts for drip fertigation of rapeseed were N at 138 kg·hm-2, P2O5 at 61.5 kg·hm-2 and K2O at 57 kg·hm-2, resulting in a yield potential of 3 000 kg·hm-2. Minimal soil water contents that remained 55% (of soil saturated water content) at the bud stage, 60% at the early blossom stage, 65% at the full blossom stage, and 55% at the pod stage were suitable to get high water use efficiency in the experimental area. |