脱硫石膏改良碱化土壤过程中的向日葵苗期盐响应研究

由于脱硫石膏的主要成分为CaSO₄，可以用来改良碱化土壤，但施加脱硫石膏同时也增加了土壤中的盐分含量。该文通过盆栽试验研究苗期向日葵在不同脱硫石膏水平和不同淋洗水平条件下向日葵出苗、土壤化学性质和土壤淋出液性质的变化规律。试验设计8个处理，4个脱硫石膏水平(0、7.5、15和22.5 t/hm²)和2个淋洗水平(750和1200 m³/hm²)。研究表明：施加脱硫石膏增加了向日葵的出苗率，降低了土壤的碱化度(ESP)、pH和全盐量(TDS)，但过量施加脱硫石膏也会抑制作物的出苗和生长；淋洗可以提高脱硫石膏的改良效率。根据试验结果推测当ESP＝63.5、pH＝9.15时，最佳脱硫石膏的投放量为13.65 t/hm²。该试验脱硫石膏用量7.5 t/hm²、淋洗水量1200 m³/hm²的处理碱化土壤改良效果最佳，向日葵出苗率达到了92.5%，ESP、pH值和TDS分别由初始的63.5%、9.15%和0.65%降到了15%、7.7%和0.15%以下。

Salinity effect on sunflower at seedling stage during improving sodic soils reclaimed with by-product from flue gas desulphurization(BFGD)

Because the main composition of by-product from flue gas desulphurization(BFGD) is CaSO₄, it can be used for improving sodic soils, at the same time the content of salt in the soil is increased because of exerting BFGD. A pot experiment was conducted to study the law of sunflower emerging, soil chemical properties and soil leachate properties under different BFGD levels and different leaching levels. There were eight treatments designed in this experiment, including four BFGD levels(0, 7.5, 15 and 22.5 t/hm²)and two leaching levels(750 and 1200 m³/hm²). Results indicated that the germination rate of sunflower was increased, Exchangeable Sodium Percentage(ESP), pH value and Total Dissolved Salts(TDS) were decreased by applying the by-product, but excessive application of BFGD also had an effect on germination and growth of sunflower, and leaching could improve efficiency. It was inferred that the best BFGD requirement was 13.65 t/hm² when ESP=63.5, and pH=9.15 according to the test result. The result of the 4th treatment (7.5 t/hm² BFGD and 1200 m³/hm² leaching water) was the best in this experiment, the germination rate of sunflower is up to 92.5%, ESP, pH and TDS had dropped to 15%, 7.7% and 15% from initial 63.5, 9.15 and 0.65%, respectively.