为寻求河西冷凉灌区春茬娃娃菜(Brassica pekinensis)适宜的水肥管理模式，以当地春茬主栽娃娃菜品种耐寒金黄后为试材，研究了不同水肥组合对娃娃菜叶球生长和叶片光合参数的影响。结果表明，灌水量、施肥量及水肥交互作用均不同程度影响娃娃菜生长和光合特性，且施肥量的影响最大，水肥交互作用的影响次之。相同施肥条件下随着灌溉量的增大叶球横径和纵径均表现出明显的上升趋势，超过一定范围后逐渐下降；灌水下限控制在田间持水量的70%(中水)和80%(高水)处理后娃娃菜叶球横径和纵径随着施肥量的升高均呈先增加后减小的趋势。全生育期施肥量为N 330 kg/hm2、P2O5 195 kg/hm2、K2O 450 kg/hm2的施肥条件下增大灌水量，叶片净光合速率(Pn)、气孔导度(Cond)、蒸腾速率(Tr)均呈先增大后减小的趋势，而叶片胞间CO₂浓度(Ci)呈先减小后增大的趋势；灌水下限控制在田间持水量的70%的灌溉水平下增加施肥量，提高了娃娃菜叶片净光合速率(Pn)、气孔导度(Cond)、蒸腾速率(Tr)，降低了娃娃菜叶片胞间CO₂浓度(Ci)。随着施肥量的增加，莲座期、结球期和采收期叶片净光合速率(Pn)、气孔导度(Cond)和蒸腾速率(Tr)均呈先升高后降低的趋势，而叶片胞间CO₂浓度(Ci)先降低后升高。不同水肥耦合模式以中水中肥处理(灌水下限控制在田间持水量的70%，施N 330 kg/hm2、P2O5 195 kg/hm2、K2O 450 kg/hm2)表现最优，较低水高肥处理(灌水下限控制在田间持水量的60%，施N 380 kg/hm2、P2O5 224 kg/hm2、K2O 518 kg/hm2)娃娃菜叶球横径和纵径分别提高了18.72%、10.98%，中心柱长则降低了31.89%；叶片净光合速率、气孔导度、蒸腾速率分别提高了13.10%、27.52%、22.26%，叶片胞间CO₂浓度降低了8.07%。综合考虑娃娃菜生长状况和光合利用特性，认为甘肃河西冷凉灌区春茬娃娃菜最为适宜的水肥组合模式是灌水下限控制在田间持水量的70%，全生育期施肥量为N 330 kg/hm2、P2O5 195 kg/hm2、K2O 450 kg/hm2。

This study aimed to identify an optimal water and fertilizer management model for spring baby cabbages (Brassica pekinensis) in the Hexi cold irrigation area. Using the local spring baby cabbage variety Cold-resistant Gold Queen as the experimental material, effects of different water-fertilizer combinations on the growth of leaf head and leaf photosynthetic parameters were investigated. Results showed that irrigation capacity, fertilization rate, and water-fertilizer interaction all significantly affected cabbage growth and photosynthetic characteristics, with fertilization rate having the greatest impact, followed by water-fertilizer interaction. Under the same fertilization conditions, as irrigation capacity increased, both the horizontal and vertical diameters of cabbage heads increased significantly, but they began to decrease after reaching a certain threshold. When the irrigation lower limit was controlled at 70% (medium water) and 80% (high water) of the field water holding capacity, the horizontal and vertical diameters of cabbage heads showed an initial increase followed by a decrease as fertilization rate increased. When the fertilization rate was N 330 kg/ha, P2O5 195 kg/ha, and K2O 450 kg/ha, increasing irrigation capacity caused net photosynthetic rate(Pn), stomatal conductance(Cond), and transpiration rate(Tr) to initially increase and then decrease, while intercellular CO₂ concentration (Ci) initially decreased and then increased. Under the irrigation level where the lower limit was controlled at 70% of field water holding capacity, increasing the fertilization rate improved the net photosynthetic rate (Pn), stomatal conductance(Cond), and transpiration rate (Tr) of cabbage leaves, while reducing the intercellular CO₂ concentration(Ci). As the fertilization rate increased, the net photosynthetic rate(Pn), stomatal conductance(Cond), and transpiration rate(Tr) of the leaves during rosette, head formation, and harvesting stages all showed an initial increase followed by a decrease, while the intercellular CO₂ concentration(Ci) initially decreased and then increased. Among the different water-fertilizer coupling models, the medium water and medium fertilizer treatment (irrigation lowerlimit controlled at 70% of field water holding capacity, fertilization of N 330 kg/ha, P2O5 195 kg/ha, and K2O 450 kg/ha) performed the best. The lower water and high fertilizer treatment (irrigation lower limit controlled at 60% of field water holding capacity, fertilization of N 380 kg/ha, P2O5 224 kg/ha, and K2O 518 kg/ha) increased the horizontal and vertical diameters of cabbage heads by 18.72% and 10.98%, respectively, while the center column length decreased by 31.89%. The leaf net photosynthetic rate, stomatal conductance, and transpiration rate increased by 13.10%, 27.52%, and 22.26%, respectively, while the intercellular CO₂ concentration decreased by 8.07%. Considering the growth conditions and photosynthetic utilization characteristics of baby cabbage, it is concluded that the most suitable water-fertilizer combination model for spring baby cabbage in the Hexi cold irrigation area of Gansu is the irrigation lower limit controlled at 70% of field water holding capacity, with a fertilization rate of N 330 kg/ha, P2O5 195 kg/ha, and K2O 450 kg/ha throughout the growth period.

S634.1

国家自然科学基金(32060678)；甘肃省自然科学基金(22JR5RA761)；甘肃省农业科学院重点研发计划(2022GAAS26)。