典型植物根系对紫色土化学属性和化学蚀变指数的影响  

Influence of Typical Plant Roots on Chemical Properties and Chemical Alteration Index of Purple Soil

作　　者：李雪 李春培 李永梅[1] 范茂攀[1] 赵吉霞 LI Xue;LI Chunpei;LI Yongmei;FAN Maopan;ZHAO Jixia(College of Resources and Environment,Yunnan Agricultural University,Kunming 650201,China)

机构地区：[1]云南农业大学资源与环境学院,昆明650201

出　　处：《土壤》2024年第2期425-432,共8页Soils

基　　金：国家自然科学基金项目(42007002);云南省基础研究计划项目(202101AT070220)资助。

摘　　要：为探究植物根系形态对紫色土风化的影响,以云南元谋干热河谷区典型植被(锥连栎、华西小石积、牛筋草和裸地)覆盖条件下的紫色土为研究对象,研究了不同植被类型根系在不同土层的分布特征及其对各土层养分含量和化学蚀变指数(CAI)的影响。结果表明:裸地、乔木、灌木、草本覆盖下紫色土化学蚀变指数分别为73.98~78.87、78.53~84.68、77.89~82.18、77.91~81.04,且均表现为随土层深度增加而降低。各植被的根系均集中分布于0~20 cm土层,不同植物根系体积存在明显差异,乔木、草本和灌木覆盖下的根系体积与裸地相比分别增加145.17%、144.78%、74.98%,乔木、灌木和草本的根系表面积与裸地相比分别增加651.16%、610.79%、181.62%。土壤中养分含量随土层深度的增加而降低。随着土层深度的增加,有机质、碱解氮、有效磷和速效钾含量呈降低趋势,裸地和乔木覆盖下的pH呈增加趋势,而草本和灌木覆盖下的pH则呈相反趋势。相关性分析结果表明,土壤的CAI值与土壤有机质、碱解氮含量呈显著正相关(P<0.05),相关系数高达0.520、0.591;土壤p H、有效磷含量与土壤CAI值呈显著负相关(P<0.05),土壤CAI值与根系体积、根系表面积呈极显著正相关(P<0.01),相关系数高达0.693、0.621。综上,植物根系对于土壤的化学风化具有较明显的促进作用。In this study,the purple soils under different typical vegetation cover conditions(Quercus franchetii Skan,tree;Osteomeles schwerinae C.K.Schneid,shrub;Eleusine indicate(L.)Gaerth,grass)were selected in the dry-hot valley area of Yuanmou of Yunnan Province in order to investigate the effects of root morphological characteristics in different soil layers on soil nutrient contents and chemical alteration index(CAI).The results showed that soil CAI was ranged from 73.98–78.87 for bare soil(CK),78.53–84.68 under trees,77.89–82.18 under shrubs and 77.91–81.04 under grasses,respectively,and all were decreased with the increase of soil depth.The roots of all kinds of plants were concentrated within the 0–20 cm soil layer,and plant type significantly affected root volume,compared to CK,root volume was enhanced by 145.17%under trees,144.78%under grasses and 74.98%under shrubs,respectively;and root surface area was increased by 651.16%under trees,610.79%under shrubs and 181.62%under grasses,respectively.Soil nutrient contents were generally decreased with the increase of soil depth,particularly for the contents of organic matter(SOM),alkali-hydrolyzale(AN),available phosphorus(AP)and available potassium(AK),soil pH showed an increasing trend in CK and under trees,but showed a decreasing trend under grasses and shrubs.The results of correlation analysis showed that soil CAI value was significantly positively correlated with SOM and AN content,with correlation coefficients as high as 0.520 and 0.591(P<0.05);soil pH and AP content were significantly negatively correlated with soil CAI value(P<0.05),and soil CAI value was highly significantly positively correlated with root volume and root surface area,with correlation coefficients as high as 0.693 and 0.621(P<0.01).respectively.In conclusion,plant root distribution has a more significant contribution to the chemical weathering of purple soils.

关 键 词：植被类型 根系形态 土壤养分 化学蚀变指数(CAI) 紫色土 

分 类 号：S1[农业科学—农业基础科学]