中文摘要：

研究了滴灌水质与灌溉频率对棉花苗期生长的影响。试验土壤为砂壤土（砂粒68％、粉粒24％、粘粒8％），土壤初始含盐量为o．8％。灌溉水质有3个水平，分别为CK（自来水）、S10（SAR=10，EC=3）与S5（SAR=5，EC=3）；灌溉频率有3个水平，分别为高频（每4d）、中频（每8d）与低频（每16d）。一条滴灌管灌溉2行棉花，棉花的行距为40cm，株距为10cm。试验结果表明，在高含盐土壤中，高频灌溉时，水质对棉苗生长的影响更大；微咸水灌溉有利于棉花苗期生长。灌溉频率对地上、地下各生长指标与总干重均有显著影响。微咸水灌溉时，地上部分生长指标与总干重在中频灌溉时均为最大，而根干重与根总长却均随灌溉频率的降低而增加，这表明棉苗在中频灌溉时所受的水分与盐分综合胁迫最小。灌溉水质与频率对根冠比均有显著影响，降低灌溉频率有利于棉花苗期根系发育。

英文摘要：

Effects of irrigation water quality and irrigation frequency was investigated on growth parameters of cotton seedling in an unheated rain preventing greenhouse. Sandy loam （sand 68%, silt 24% and clay 8%） with initial salt content of 0.8% is used for the experiment. The irrigation water quality has 3 levels, which is CK （tap water）, S10 （SAR=10, EC=3） and S5 （SAR=5, EC=3） respectively. The irrigation frequency has 3 levels, which is high frequency （4 days）, moderate frequency （8 days） and low frequency （16 days） respectively. Row spacing of cotton is 40 cm, and plant spacing is 10 cm. The drip line is located in the middle of 2 rows. The Result indicates that impact of water quality on growth parameters of cotton seedling irrigated with high frequency is more significant than moderate and low frequency. Irrigating with saline water can improve growth of cotton seedlings. Irrigation frequency affects overground and under- ground growth parameters and total dry weight significantly. The overground growth parameters and total dry weight of treatment irrigated with moderate frequency is biggest among 3 irrigation frequency levels, whereas the roots dry weight and total length increase with decreasing irrigation frequency. It indicates that cotton irrigated with moderate frequency receive less integrated stress of water and salinity than high and low frequency. Both water quality and irrigation frequency affect ratio of root and canopy significantly. Low irrigation frequency makes for development of cotton root system.