烟-稻复种连作年限对土壤钙镁硫含量的影响

对湖南烟-稻复种连作田与相邻未种烟的双季稻田进行土壤样品的采集和对比分析。结果表明:耒阳植烟1～5年土壤的交换性钙含量高于对照,但植烟5年后土壤交换性钙含量与对照相比则有不同程度的降低;浏阳、宁远植烟1年土壤的交换性钙含量低于对照,但植烟5～20年的土壤交换性钙含量与对照相比有不同程度的升高。植烟1年土壤的交换性镁含量高于对照,但随着烟-稻复种连作年限的增加,烟-稻复种连作田与对照相比土壤交换性镁的含量均有不同程度的降低。在植烟年限1～15年之间,随植烟年限的增加,植烟土壤全硫和有效硫含量显著增加;植烟年限超过15年,植烟土壤全硫和有效硫含量趋于平稳。

The Effect of the Years of Continuous and Multiple Cropping of Flue-cured Tobacco-Rice on Soil Ca,Mg and S Content

Field sampling experiment was carried out to analyze and estimate exchange magnesium,exchange calcium,total sulfur and available sulfur content of Leiyang,Liuyang and Ningyuan in Hunan province.The result showed that the exchange calcium contents of planting-tobacco soil were higher than the control from 1 to 5 years but they tended to decline after 5 years of continuous and multiple cropping of flue-cured tobacco-rice in Leiyang.The exchange calcium contents of 1 year of planting-tobacco soil in Liuyang and Ningyuan were lower than the control but they were various degrees higher than the control from 5 to 20 years.The exchange magnesium contents of 1 year of planting flue-cured tobacco soil were higher than the control.They were various degrees lower than the control along with the years of continuous and multiple cropping of flue-cured tobacco-rice.The available sulfur and total sulfur contents were remarkable increased from 1 to 15 years and were steady after 15 years in continuous tobacco planting soil.