土壤改良剂对灌溉咸水冬小麦光合和蒸腾的影响

Effects of soil improvement agents on photosynthesis and transpiration of saline-water irrigated winter wheat

在天津滨海地区高水位、黏重土壤利用田间小区试验研究调盐土壤改良对微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。结果表明,冬小麦播种前采用适当土壤改良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。冬前施用75kg.100m 2改良剂Ⅱ(风化褐煤40%+磷石膏40%+脱硫石膏20%)有利于提高冬小麦灌浆期的光合速率,有降低抽穗期、灌浆期小麦蒸腾速率的效果;小麦冬前施用45 kg.100m 2改良剂I(风化褐煤20%+磷石膏40%+脱硫石膏20%+沸石粉20%)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;土壤改良对咸水灌溉冬小麦的气孔导度有明显降低效应,冬前施用30 kg.100m 2改良剂Ⅲ(磷石膏40%+脱硫石膏20%+沸石粉40%)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45kg.100m 2改良剂Ⅱ混合30 kg.100m 2改良剂Ⅲ或75 kg.100m 2改良剂Ⅱ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.100m 2改良剂I混合30 kg.100m 2改良剂Ⅲ,即使较高土壤含盐量也能使冬小麦光合速率保持在较高水平,使冬小麦蒸腾速率受土壤含盐量影响较小。

Field experiment were conducted to determine the effects of soil improvement agents on photosynthetic rate,transpiration rate,stomatal conductance,chlorophyll content index of saline-water irrigated winter wheat.The experiment was conducted in high water table and sticky soil fields in coastal areas of Tianjin.The results of the study showed that adoption of appropriate soil improvement agents before winter wheat sowing increased photosynthetic rate,chlorophyll content index at heading or grain filling stage,and decreased stomatal conductance and transpiration rate at the same stages.75 kg·100m 2 soil improvement agent Ⅱ（40% weathered lignite ＋ 40% phosphogypsum ＋ 20% desulfurized gypsum） application before winter improved photosynthetic rate of winter wheat at grain-filling stage,and lowered transpiration rate of wheat at heading and grain-filling stages.45 kg·100m 2 soil improvement agent I（20% weathered lignite ＋ 40% phosphogypsum ＋ 20% desulfurized gypsum ＋ 20% zeolite powder） application before winter improved both photosynthetic and transpiration rates of winter wheat at heading stage.Saline-water irrigation significantly reduced winter wheat stomatal conductance.Stomatal conductance of winter wheat under 30 kg·100m 2 soil improvement agent Ⅲ（40% phosphogypsum ＋ 20% desulfurized gypsum ＋ 40% zeolite powder） application reduced by 52.28% at heading stage and 39.51% at grain-filling stage compared with that of winter wheat without soil improvement agent.Application of 45 kg·100m 2 soil improvement agent Ⅱ plus 30 kg·100m 2 soil improvement agent Ⅲ,or 75 kg·100m 2 soil improvement agent Ⅱ before winter significantly increased chlorophyll content index of winter wheat at both heading and grain-filling stages.Application of 45 kg·100m 2 soil improvement agent I plus 30 kg·100m 2 soil improvement agent Ⅲ before winter maintained photosynthetic rate of saline-water irrigated winter wheat at high levels even under higher soil salt content.This shielded winter wheat transpiration rate from the effects of soil salinity.