关键词: 抗性, 抗性

Abstract: A field experiment was conducted to study the effects of different moisture conditions and fertilizing amount on the yield, nutrient absorption (N, P and K) and quality of lettuce (Lactuca sativa var. angustana Irish). The results showed that the yield of lettuce under treatment of high water and high fertilization(W₁F₁) was the highest, it’s 87019.05 kg/hm². But the yield of medium water and high fertilization(W₂F₁) treatment was not significantly different from that of W₁F₁, also reached 85777.28 kg/hm². The two treatments’yield were 20.40% and 18.68% higher than that of the low water medium fertilization (W₃F₂) treatments, which was the lowest yield treatment. The N, P and K content of lettuce organs present a downtrend along with the decrease of fertilizing amount, but raised first and then decreased with the decline of irrigation lower limit. That is, W₂ (65% field capacity) irrigation lower limit was a good condition to nutrient absorption. The Vc and soluble solid content of lettuce edible parts under W₂ (65% field capacity) irrigation lower limit were higher than that of W₁ (75% field capacity) irrigation lower limit and W₃ (55% field capacity) irrigation lower limit treatments. The nitrate content increased with the decline of irrigation lower limit and increasing of fertilizing amount. The soluble sugar content presented different change rule under different irrigation lower limit along with the change of fertilizing amount. To sum up, combination treatment with medium water and high fertilization amount, that is, 65% irrigation lower limits and fertilizing amount N 296.7 kg/hm², P₂O₅ 70.2 kg/hm², K₂O 171.6 kg/hm² were the appropriate irrigation and fertilization scheme for lettuce grows in Hexi area of Gansu Province.