Abstract:

In order to explore the scientific irrigation and fertilization system of water saving， fertilizer saving， high yield and high efficiency of mini Chinese cabbage （Brassica pekinensis） in cold-cool irrigation area of Hexi， the mini Chinese cabbage planted in autumn were the research object， ‘Gold Queen’ was used as a test material， and the effects of different water levels （low， H1； middle， H2； high， H3） combined with 3 fertilizer levels （low， F1； middle， F2； high， F3） on water consumption， photosynthetic characteristics and yield of mini Chinese cabbage under drip irrigation were studied. The results showed that irrigation， fertilization， water and fertilizer coupling all affected the water consumption， photosynthetic characteristics and yield of mini Chinese cabbage. The water consumption intensity of mini Chinese cabbage reached the maximum at the early stage of heading under different water and fertilizer coupling effects. The water consumption intensity of low water， medium water and high water treatment was 0.003 2， 0.003 3 and 0.003 4 m³·d^-1·m^-2， respectively. Under the water and fertilizer coupling mode， the treatment of medium water and fertilizer increased the chlorophyll content， leaf net photosynthetic rate， stomatal conductance， transpiration rate and economic yield by 4.4%， 10.4%， 27.3%， 23.6% and 62.3% respectively， and decreased the intercellular CO₂ concentration by 3.0%， compared with the treatment of low water and low fertilizer. Comprehensive analysis showed that the suitable water and fertilizer coupling mode of autumn mini Chinese cabbage in cold-cool irrigation area of Hexi corridor in Gansu province was as follows： the lower limit of irrigation was 70% of field capacity， and the amounts of N， P₂O₅，_{K2O fertilizer were 330， 195， 450 kg·hm^-2. Above results provided theoretical bases and technical supports for water and fertilizer management of autumn mini Chinese cabbage in Hexi cold-cool irrigation area.}

Key words: mini Chinese cabbage, drip irrigation under mulch, water consumption characteristics, fertilizer application, photosynthetic characteristics

摘要：

为探求河西冷凉灌区秋茬小型大白菜（Brassica pekinensis）节水节肥、高产高效的科学灌溉施肥制度，以当地秋茬主栽品种‘金皇后’为试材，研究膜下滴灌条件下不同水肥（低水，H1；中水，H2；高水，H3；低肥，F1；中肥，F2；高肥，F3）组合对小型大白菜耗水及其叶片光合特性的影响。结果表明，灌水量、施肥量及其交互均不同程度地影响小型大白菜的耗水和光合特性及产量。在不同水肥耦合作用下，小型大白菜耗水强度均于结球初期达到最大值，低水、中水和高水处理的耗水强度分别为0.003 2、0.003 3、0.003 4 m³·d^-1·m^-2。水肥耦合模式下，中水中肥处理小型大白菜的叶绿素含量、叶片净光合速率、气孔导度、蒸腾速率、经济产量较低水低肥处理分别提高4.4%、10.4%、27.3%、23.6%、62.3%，叶片胞间CO₂浓度降低3.0%。综合考虑小型大白菜的耗水、产量和光合利用等特性，甘肃河西走廊冷凉灌区露地秋茬小型大白菜的适宜水肥耦合模式为灌水量控制在田间持水量的70%，N、P₂O₅、K₂O的施用量分别为330、195、450 kg·hm^-2。以上结果为河西冷凉灌区秋茬小型大白菜水肥管理提供理论依据和技术支持。

关键词: 小型大白菜, 膜下滴灌, 耗水特征, 施肥, 光合特性