盐碱地施用脱硫石膏对土壤养分及油葵光合特性的影响

Effects of Desulfurized Gypsum Addition on Saline-alkali Soil Nutrients and Photosynthetic Characteristics of Cultivated Oil-sunflower

通过分析宁夏平罗西大滩不同改良年份盐碱地土壤养分含量,测定油葵(Helianthus annuus)光合日变化曲线、光响应曲线和油葵产量,研究了施用脱硫石膏对盐碱地土壤改良及油葵光合特性的影响.结果表明,在盐碱土壤上施用燃煤电厂脱硫石膏后,土壤电导率、pH值随土壤改良年限增加而逐年下降,土壤有机质含量、碱解氮、有效磷和速效钾则逐年上升.随着土壤改良年限增加,油葵叶片净光合速率、蒸腾速率、气孔导度、胞间二氧化碳浓度均明显下降,气孔限制值和水分利用效率也明显下降(P<0.01).同时,随着改良年限增加,油葵叶片暗呼吸速率、光饱和点和最大净光合速率增加,而光补偿点降低.施用脱硫石膏后油葵盘径、百粒重和产量随土壤改良年限增加也显著提高(P<0.05).因此,施用燃煤电厂脱硫石膏能够显著地改良盐碱地土壤、提高油葵叶片光合能力,从而促进作物生长、提高作物产量.

The soil nutrient content of the ameliorated saline-alkali soils with different ages, and the diurnal courses curve of photosynthetic parameters, photosynthetic light response curve and yield of oil-sunflower （Helianthus annuus） grown on the ameliorated soils were measured to investigate the effects of desulfurated waste residue additions on the saline-alkali soils. The results showed that the soil electronic conductivity and pH value decreased while the soil organic matter, the concentration of available nitrogen （N）, phosphorus （P） and potassium （K） increased with the ameliorating ages. And the net photosynthetic rate （Pn）, transpiration rate （Tr）, stomatal conductance （Gs） and intercellular CO2 concentration （Ci） also increased markedly, but the water use efficiency （WUE） and stomatal limiting value （Ls） decreased. Meanwhile, the dark respiration rate （Rday）, maxmum photosynthetic rate （Amax）, light saturation point （LSP） increased obviously, while the light compensation point （LCP） decreased. A similar dramatic elevation was also found on the diameter size, plant weight and final yield of oil-sunflower. It was concluded that application of desulfurized gypsum can significantly facilitate the saline-alkali soil amelioration, enhance leaf photosynthetic capacity, promote crop growth and ultimately increase crop yield. Fig 2, Tab 3, Ref 29