土壤调盐改良对咸水灌溉冬小麦光合和蒸腾的影响

在天津滨海地区高水位、黏重土壤利用田间小区试验研究土壤调盐改良技术对咸水灌溉的冬小麦光合速率、蒸腾速率、气孔导度、叶绿素含量指数等生理指标的影响,试验结果表明,冬小麦播种前采用适当土壤调盐改良技术能够提高冬小麦抽穗期、灌浆期的光合速率、叶绿素含量指数,降低气孔导度、蒸腾速率.小麦冬前施用75 kg/100 m2改良剂(40％风化褐煤+40％磷石膏+20％脱硫石膏)有利于提高冬小麦灌浆期的光合速率,有降低抽穗期、灌浆期小麦的蒸腾速率的效果,冬前施用45 kg/100 m2改良剂(20％风化褐煤+40％磷石膏+20％脱硫石膏+20％沸石粉)对提高冬小麦抽穗期光合速率有利,同时也提高抽穗期小麦的蒸腾速率;土壤调盐改良剂对咸水灌溉冬小麦的气孔导度有明显抑制作用,冬前施用30kg/100 m2改良剂(40％磷石膏+20％脱硫石膏+40％沸石粉)的冬小麦气孔导度与不采用改良措施相比,抽穗期降低52.28％,灌浆期降低39.51％;冬前施用45 kg/100 m2或75 kg/100 m2改良剂(40％风化褐煤+40％磷石膏+20％脱硫石膏)和30 kg/100 m2改良剂(40％磷石膏+20％脱硫石膏+40％沸石粉)均能够显著提高抽穗、灌浆期冬小麦的叶绿素含量指数;冬前施用45 kg/100m2改良剂(20％风化褐煤+40％磷石膏+20％脱硫石膏+20％沸石粉)和30 kg/100 m2改良剂(40％磷石膏+20％脱硫石膏+40％沸石粉),即使在较高土壤含盐量也能够使冬小麦光合速率保持在较高水平,使冬小麦蒸腾速率受到土壤含盐量影响不明显.

Effects of Soil Improvement Techniques on Photosynthesis and Transpiration of Winter Wheat Irrigated with Saline Water

Field experiment of effects of soil improvement techniques on photosynthetic rate,transpiration rate,stomatal conductance,chlorophyll content index and other physiological characters of winter wheat irrigated with saline water were carried out on high ground water level and sticky soil in coastal area of Tianjin.The results showed that adoption of appropriate soil improvement techniques before sowing of winter wheat could increase photosynthetic rate,chlorophyll content index of winter wheat at heading stage or grain filling stage,whild decrease stomatal conductance,transpiration rate at the same time.Applying 75 kg/100 m2 conditioner(40% weathered lignite+40% phosphogypsum+20% desulfurized gypsum) before winter could improve the photosynthetic rate of winter wheat at grain-filling stage,lower transpiration rate of wheat at heading and grain-filling stage.Applying 45 kg/100 m2 conditioner(20% weathered lignite+40% phosphogypsum+20%gypsum+20%zeolite powder) before winter could improve both photosynthetic rate and transpiration rate of winter wheat at heading stage.Soil conditioner could also reduce stomatal conductance of winter wheat irrigated with saline water significantly.The stomatal conductance appling 30 kg/100 m2 conditioner(40% phosphogypsum+20% gypsum+40% zeolite powder) was reduced by 52.28% at heading stage and by 39.51% at grain-filling stage compared to that without soil improvement measures.Application of 45 kg/100 m2 or 75 kg/100 m2 conditioner(40% weathered lignite+40% gypsum+20% gypsum) and 30 kg/100 m2 modifier(40% phosphogypsum+20% desulfurized gypsum+40% zeolite powder) before winter were able to significantly increase chlorophyll content index of winter wheat at both heading stage and filling stage.Application of 45 kg/100 m2 conditioner(20% weathered lignite+40% phosphogypsum+20% desulfurized gypsum+20% zeolite powder) and 30 kg/100 m2 conditioner(40% phosphogypsum+20% desulfurized gypsum+40% zeolite powder) before winter could maintain photosynthetic rate of winter wheat irrigated with saline water at a higher salt content,and make winter wheat transpiration rate less affected by soil salinity.