重庆典型烟区土壤有机质及其活性组分的分布特征

为了解重庆典型烟区土壤有机质数量和质量状况,采用现场调查与室内分析相结合的方法,对重庆彭水、丰都和巫山3个典型烟区土壤有机质及其活性组分的分布特征及相互关系进行了研究。结果表明,3个典型烟区土壤有机质(SOM)含量为3.35～53.94 g/kg,在适宜植烟范围(15～30 g/kg)内的比例呈现出丰都>巫山>彭水的趋势,变异系数为巫山烟区大于丰都和彭水烟区。用33、167和333 mmol/L KMnO₄测得的高活性有机质(HLOM)、中活性有机质(MLOM)、活性有机质(LOM)占SOM的比例分别表现为巫山>丰都>彭水、丰都>巫山>彭水、丰都>彭水>巫山,与各烟区的SOM含量均呈极显著正相关,说明土壤活性组分不仅可以很好的反映土壤碳素动态变化,还可用作评价重庆植烟土壤肥力和土壤质量的指标之一。

Distribution Characteristics of Soil Organic Matter and its Active Ingredients in the Typical Tobacco-growing Regions in Chongqing

To understand the quantity and quality situation of soil organic matter in the typical tobacco-growing regions, soil samples were collected in tobacco growing regions of three prefectures in Chongqing including Pengshui, Fengdu and Wushan. The contents of soil organic matter and its active ingredients were determined. The results showed that the contents of soil organic matter (SOM) ranged from 3.35 to 53.94 g/kg. The percentages of soil samples with SOM contents in the appropriate range (15-30 g/kg) for tobacco growing followed the order of Fengdu> Wushan> Pengshui, while the CV for Wushan was higher than those of Fengdu and Pengshui. As the SOM was divided into high labile organic matter (HLOM), mid-labile organic matter (MLOM) and labile organic matter (LOM) with 33,167 and 333 mmol/L KMnO₄, respectively, their percentages in the SOM followed the order of Wushan>Fengdu>Pengshui, Fengdu>Wushan>Pengshui and Fengdu>Pengshui>Wushan, respectively. The content of HLOM, MLOM, LOM were significantly and positively correlated with the content of SOM, indicating that the active ingredient of soil organic matter may well reflect the dynamic changes of soil carbon, and therefore can be used as a indicator for the evaluation of soil fertility and soil quality.