摘要
土壤有机质含量是土壤分析的重要指标,对土壤结构、物理特征与肥力等有重要的影响,因此对土壤有机质含量的准确测定是开展土壤相关研究的前提。采用灼烧法(350、450、550、650℃4个灼烧温度与2、4、6、8、10、12 h 6个灼烧时间)和重铬酸钾容量法对取自云南昭通一高植被覆盖度的斜坡林下土壤有机质含量进行测定,结果表明:土壤有机质含量(soil organic matter,SOM)随土壤深度增加而递减,重铬酸钾容量法的测定结果较为准确和稳定,灼烧法的灼烧温度和灼烧时间对结果有明显影响,灼烧温度越高,烧失量越大,测得的SOM越高,测定结果的准确性越低;灼烧2 h内烧失量显著增加,灼烧4 h以后,SOM基本稳定不变;通过分析,对结果准确性要求较高时,建议采用重铬酸钾容量法;若样品量大且需快速测定时,建议采用灼烧法(灼烧温度不宜超过450℃,灼烧时间为4 h)。同时研究还发现SOM对土壤结构特征有着明显影响,取样点土壤具有高有机质含量的性质,导致土壤具有高孔隙度-低容重-高含水率的物理特征。
The soil organic matter content is an important indicator of soil analysis,and has an important influence on the soil structure,physical characteristics and fertility,thus the accurate determination of soil organic matter content is the premise of related research regarding soil.The burning method(four burning temperatures:350℃,450℃,550℃and 650℃and six burning time:2 h,4 h,6 h,8 h,10 h and 12 h),and potassium dichromate volumetric method were used to determine the organic content of the soil from the slope forest with high vegetation coverage in Zhaotong city,Yunnan province.The results show as follows.The soil organic matter decreases with the increase of soil depth,the determination result of potassium dichromate volumetric method is relatively accurate and stable,the burning temperature and time of the burning method have an obvious influence on the results,the higher the burning temperature is,the greater the loss on ignition will be,the higher the measured soil organic matter(SOM)will be,and the lower the accuracy of the measurement results will be,the loss on ignition increases significantly within 2 h of burning,soil organic matter is basically stable after burning for 4 h,it's suggested to adopt potassium dichromate volumetric method when the accuracy of the results is high upon analysis,and to adopt the burning method(burning temperature should not exceed 450℃and burning time is 4 h)if there are plenty of samples which need to be quickly determined.According to the research,it's also found that soil organic matter has a significant effect on soil structure characteristics,and the soil at the sampling site is characterized by high organic matter content,as a result,the soil has the physical characteristics-high porosity,low bulk density and high water content.
作者
陶真鹏
徐宗恒
丁俊楠
张宇
TAO Zhen-peng;XU Zong-heng;DING Jun-nan;ZHANG Yu(Department of Geography, Yunnan Normal University, Kunming 650500, China)
出处
《科学技术与工程》
北大核心
2022年第10期3892-3901,共10页
Science Technology and Engineering
基金
云南省科技厅应用基础研究面上项目(202101AT070138)。
关键词
土壤有机质含量
灼烧法
重铬酸钾容量法
土壤结构
soil organic matter
burning method
potassium dichromate volumetric method
soil structure
作者简介
第一作者:陶真鹏(1997—),男,苗族,云南昭通人,硕士研究生,研究方向:山地灾害与遥感应用,E-mail:1195819845@qq.com;通信作者:徐宗恒(1987—),男,汉族,云南永胜人,博士,副教授,研究方向:山地灾害与地质环境,E-mail:553790356@qq.com。
