湘西典型植烟土壤酸碱缓冲特性及影响因素

为探明山地植烟土壤酸碱缓冲特性，采集了湘西山区烤烟典型生产区的28个土壤样本，采用酸碱滴定法和灰色关联法分析了湘西山地植烟土壤酸碱缓冲特性以及土壤缓冲容量与各影响因素之间的量化关系。结果表明：湘西山地植烟土壤酸碱缓冲量为11.35~43.29 mmol·kg^-1，平均为17.26 mmol·kg^-1，黄棕壤的酸碱缓冲量（11.35~43.29 mmol·kg^-1）显著高于黄壤（11.79~20.70 mmol·kg^-1）。有78.57%的样本对酸碱敏感，黄壤土是否对酸敏感由有机质含量决定，黄棕壤土是否对酸敏感与pH和有机质含量密切相关。对于同一土壤类型，有机质和黏粒含量与酸碱缓冲容量显著正相关；对于黄棕壤，酸碱缓冲容量还与pH和阳离子交换量呈显著正相关，与交换性酸和交换性铝呈显著负相关。主要土壤类型之间缓冲性能存在较大差异，黄壤土酸碱缓冲性能主要受土壤有机质、阳离子交换量和黏粒含量的影响；黄棕壤土酸碱缓冲性能主要受pH、阳离子交换量和有机质的影响。在生产中应采用合理施用化肥、增施有机肥、调节土壤酸性等措施提高植烟土壤酸碱缓冲性能，为优质烟叶生产创造良好的生态环境。

Characteristics and driving factors of acid-base buffer of typical tobac-co-planting soils in western Hunan Province

To determine the characteristics of pH buffer of soils cultivated with tobacco in the mountain regions that are under long-term fertilizer application, a total of 28 soil samples were collected in areas of typical flue-cured tobacco cultivation in mountain regions in western Hunan Province. The pH buffer characteristics of collected soils were analyzed using both titration curve and gray correlation methods. Then quantitative relationships and the driving factors of soil acid-base buffer characteristics were also investigated. The results showed that the range of pH buffer of soils cultivated with tobacco in western Hunan Province was 11.35-43.29 mmol·kg^-1 and the average was 17.26 mmol·kg^-1. Acid-base buffer of yellow brown soil (11.35-43.29 mmol·kg^-1) was significantly higher than that of yellow soil (11.79-20.70 mmol·kg^-1). While the sensitivity of yellow soil to acid was determined by the content of soil organic matter, that of yellow brown soil to acid was closely related to pH and organic matter content. Also while 78.57% of the samples were sensitive to both acid and base, soil type, organic matter contents, and clay content were positively correlated with pH buffer capacity. For yellow brown soil, pH buffer capacity was also positively correlated with pH and cation exchange capacity. However, it was negatively correlated with exchangeable acid and aluminum. The performances of pH buffer of two soil types were quite different. pH buffer capacity of yellow soil was mainly affected by soil organic matter content, cation exchange capacity, and clay content. Then pH buffer capacity of yellow brown soil was mainly affected by pH, cation exchange capacity, and organic matter content. For production, it was necessary to use chemical fertilizers properly, to add organic fertilizer, to adjust soil acidity and to take other measures to improve pH buffer capacity of soil cultivated with tobacco. This will create a good ecological environment for the production of high quality tobacco leaves.