种稻配施改良剂对苏打盐碱土-水-作物系统氟迁移的影响

为探讨化学改良剂对苏打盐碱土稻田生态系统中氟迁移的影响，采用盆栽试验，研究硫酸铝、脱硫石膏和有机复合改良剂作用下的土壤各形态氟含量变化，以及土壤氟向水体和地上部植株的迁移情况。结果表明，化学改良剂影响苏打盐碱土—水—作物系统中氟的迁移及生物有效性。种稻后各改良剂处理的土壤水溶态氟变化范围为8.33～20.90 mg/kg,与对照相比，均呈下降趋势，其中硫酸铝处理下降得最多，降低60.15%;可交换态氟和有机束缚态氟呈增加趋势，其中有机复合改良剂处理增加得最多，分别为79.54%和86.37%;种稻前后铁锰氧化物结合态氟变化较复杂，其中硫酸铝处理无显著变化，对照处理和有机复合改良剂处理分别增加19.05%和42.03%,而脱硫石膏处理下降22.79%;残余态氟和总氟含量呈下降趋势，其中有机复合改良剂处理的残余态氟降低得最多，为35.50%,硫酸铝处理的总氟降低得最少，为10.47%,其余处理降幅为12.50%～12.55%。在水稻种植过程中，土壤中氟向水中累积释放总量为对照>有机复合改良剂>脱硫石膏>硫酸铝，与对照相比，其他3个处理分别降低3.25%,5.13%和5.1...

Effects of Rice Planting with Amendments on Fluorine Migration in Soda Saline-Alkali Soil-Water-Crop System

In order to study the effect of chemical amendments on fluorine migration in the paddy ecosystem of soda saline-alkali soil,pot experiments were conducted to study the changes of fluorine content in various forms of soil and the migration of soil fluorine to water and aboveground plants under the effects of aluminum sulfate,desulfurized gypsum and organic compound modifiers.The results showed that chemical amendments would affect the migration and bioavailability of fluorine in soda saline-alkali soil-water-crop system.After planting rice,the variation of soil water-soluble fluorine in each amendment treatment ranged from 8.33 to 20.90 mg/kg,which showed a downward trend compared with the control,of which aluminum sulfate treatment decreased the most,by 60.15%;Exchangeable fluorine and organic bound fluorine showed an increasing trend,among which the organic compound modifier treatment increased the most,by 79.54% and 86.37% respectively;The changes of iron manganese oxide bound fluorine before and after rice planting were complex,among which aluminum sulfate treatment had no significant change,the control treatment and organic compound modifier treatment increased by 19.05% and 42.03% respectively,while desulfurization gypsum treatment decreased by 22.79%;The contents of residual fluorine and total fluorine showed a downward trend,among which the residual fluorine decreased the most by 35.50% under the organic compound modifier treatment,the total fluorine decreased the least by 10.47% under the aluminum sulfate treatment,and the other treatments decreased by 12.50% to 12.55%.In the process of rice planting,the total cumulative released amount of fluorine from soil to water was control > organic compound modifier > desulfurization gypsum > aluminum sulfate.Compared with the control,the other three treatments decreased by 3.25%,5.13% and 5.19% respectively.The total migration amount of fluorine in soil migrating to rice stems,leaves and paddy was in the order of organic compound modifier > desulfurized gypsum > aluminum sulfate,the migration amount per unit soil was 0.44,0.40 and 0.25 mg/kg respectively,and the migration rates were 0.16%,0.15% and 0.09% respectively.The results of correlation analysis showed that the total amount of fluorine released from soil to water and transferred to rice stems and leaves in soil were positively correlated with soil pH,soluble salt and various forms of fluorine content,while the fluorine content of rice paddy was not affected by soil properties.Because the absorption of fluorine by rice stems and leaves under the aluminum sulfate treatment was significantly lower than that of other treatments,and the content of water-soluble fluorine in soil and the total amount of fluorine released from soil to water were also less,aluminum sulfate modifier had a better ability to reduce fluorine migration and bioavailability in soda saline-alkali paddy soil.