西北内陆旱区洋葱耗水规律试验研究

Crop Water Use of Onion (Allium cepa L.) in the Osias Arid Region of Northwest China

以白皮洋葱为试材,利用称量式蒸渗仪灌水试验,研究了不同灌水量及土壤含盐量对洋葱的耗水规律、产量和水分利用效率的影响。供试土壤分别为低盐土和高盐土,低盐土在鳞茎膨大期设置3种灌水处理,其对应的灌水下限分别为0~30 cm土层土壤含水率达到田持的80%、70%和60%,其他生长期和高盐土的全生育期灌水下限均为田持的80%。研究结果表明,鳞茎膨大期是洋葱的关键需水期;洋葱作物系数立苗期为0.50,发叶期为1.00,鳞茎膨大期为1.50,成熟期为1.25。低盐土的中水处理洋葱可获得最大产量、水分利用效率和较大的灌溉水利用效率;水分和盐分胁迫对洋葱的产量和耗水具有明显的影响。在石羊河流域洋葱鳞茎膨大期,0~30 cm土层土壤灌水下限为田持的70%左右是较适宜的灌水方案。

An experiment was conducted in the weighting lysimeters to investigate crop water consumption,yield and water use efficiency of onion（Allium cepa L.） under three irrigation levels and two soil salinity levels in the Osias arid region,northwest China.For the low salinity soil,irrigation was applied with 80%,70% and 60% of field capacity（FC） in the layer of 0 to 30 cm as its lower limit of irrigation,which are corresponding to high,moderate and low water treatment during the bulbification stage,while in other stages for low salinity soil and stages for high salinity soil,the onion was irrigated with high irrigation water.Results indicated that bulbification stage is the most critical period for onion water consumption,crop coefficient of onion is 0.50,1.00,1.50,and 1.25 respectively for the establishment,development,bulbification,and ripening stages.Maximum yield,WUE and higher IWUE can be obtained with the moderate water treatment.Onion yield and water consumption are significantly affected by water and salinity stress.In a conclusion,the proper irrigation schedule for onion growing in low salinity soil is the treatment with 70% FC in 0~30 cm layer as its lower limit of irrigation during the bulbification stage,while no water stress in the other stages,in the Oasis arid region Northwest China.