烟气脱硫石膏对滨海滩涂盐碱地的改良效果研究

在实验室条件下评估了烟气脱硫石膏不同施用量(0、5、10、25和50g/kg)对上海南汇滩涂盐碱土化学性质及对植物生长的影响.结果表明,施加适量烟气脱硫石膏可以降低滩涂土壤盐碱性,促进供试植物生长.与空白处理相比,烟气脱硫石膏施用量为25g/kg时,土壤p H和碱化度(ESP)分别显著降低5.45%和61.5%;可溶性Cl-和CO32-+HCO3-含量分别显著降低33.0%和22.7%;可溶性Ca2+和SO42-含量分别显著增加85.1%和96.3%(P0.05).试验还发现,施用量为25g/kg时土壤有机质和速效磷含量分别降低17.5%和54.0%,土壤速效钾含量提高39.5%.随烟气脱硫石膏施用量增加,番茄的果实鲜重、根鲜重和株茎的增加量分别高达144%、54.3%和9.53%;黑麦草的植株鲜重和根鲜重增加量分别高达46.6%和17.0%.但过量烟气脱硫石膏(如50g/kg)明显对植物生长不利.因此,25g/kg可推荐为改良滨海滩涂盐碱土及促进植物生长适宜和安全的烟气脱硫石膏施用量.

Amelioration of flue gas desulfurization gypsum on saline-sodic soil of tidal flats and its effects on plant growth

A set of pot experiments was conducted to assess the effect of application of flue gas desulfurization gypsum (FGD-gypsum) with different rates of (0, 5, 10, 25 and 50g/kg) on chemical properties of saline-sodic soil in Shanghai tidal flats and plant growth. The results showed that soil salinity can be decreased by appropriate rates of FGD-gypsum addition, promoting plant growth. Compared with the blank treatment, at FGD-gypsum addition rate of 25g/kg, the soil pH and alkalization degree (ESP) were reduced by 5.45% and 61.5%,contents of soluble Cl^- and CO₃^2-+HCO₃-reduced by 33.0% and 22.7%, and soluble Ca²⁺ and SO₄^2- increased by 85.1% and 96.3% respectively at significantly level of P < 0.05. The treatment also found that the content of soil organic matter and available phosphorus were reduced by 17.5% and 54.0%, and available potassium increased by 39.5% respectively. Fruit fresh weight, root fresh weight and plant stem of tomato were increased up to 144%, 54.3% and 9.53%, and plant fresh weight and root fresh weight of ryegrass were increased up to 46.6% and 17.0% by increasing rates of FGD-gypsum addition, while the excessive application of FGD-gypsum (50g/kg) seriously harmed to plant growth. FGD-gypsum application rate of 25g/kg is recommended as the optimal and safe application rate of FGD-gypsum for saline-sodic soil amendment.