喀斯特退耕地不同植被恢复阶段土壤团聚体稳定性特征  

Characteristics of Stability of Soil Aggregates at Different Vegetation Restoration Stages in Karst Reclaimed Land

作　　者：董天富 邓志豪 杨静 戴全厚[1] 聂云鹏[2,3] Dong Tianfu;Deng Zhihao;Yang Jing;Dai Quanhou;Nie Yunpeng(College of Forestry,Guizhou University,Guiyang 550025,China;Huanjiang Observation and Research Station for Karst Ecosystems,Chinese Academy of Sciences,Huanjiang,Guangxi 547100,China;Institute of Subtropical Agriculture,Chinese Academy of Sciences,Changsha 410125,China)

机构地区：[1]贵州大学林学院,贵阳550025 [2]中国科学院环江喀斯特生态系统观测研究站,广西环江547100 [3]中国科学院亚热带农业生态研究所,长沙410125

出　　处：《水土保持研究》2024年第2期33-42,共10页Research of Soil and Water Conservation

基　　金：国家自然科学基金(42161009,41807175,31971438);贵州省科学技术基金(黔科合基础-ZK[2021]一般223)。

摘　　要：[目的]探究黔中喀斯特地区黄壤和石灰土发育区耕地退耕对土壤结构和稳定性的影响,为喀斯特区水土流失防治和退耕地恢复植被效益评价提供理论依据。[方法]基于干湿筛法,对耕地(YM)和退耕后不同植被恢复阶段草地(CD)、灌丛(GC)、林地(LD)浅层(0—30 cm)土壤团聚体组成和稳定性差异特征进行了研究。[结果]两种土壤类型发育区土壤机械团聚体含量随粒径减小而降低,水稳性团聚体含量随粒径减小先降低后上升,且土壤机械团聚体均以>1 mm为主,黄壤和石灰土占比分别为82.45%,84.01%;水稳性团聚体以>2 mm为主,占比分别为53.53%,54.61%。黄壤团聚体平均重量直径(MWD)、几何平均直径(GMD)随土层深度增加而降低,石灰土则相反;黄壤退耕地的团聚体稳定性相对于石灰土更好;两种土壤MWD,GMD总体上均为YM最低,土壤结构破坏率(PAD)最高,即YM土壤团聚体稳定性最低,不同退耕植被恢复阶段土壤团聚体稳定性相对于YM皆有所提高。黄壤土壤MWD与有机质含量(SOM)、全氮(TN)显著正相关,GMD与SOM显著正相关,PAD则是与粉粒显著正相关(p<0.05);石灰土MWD,GMD与砂粒、全钾(TK)显著正相关(p<0.05),和全磷(TP)极显著负相关,PAD与砂粒、TK极显著负相关,与TP极显著正相关(p<0.01),与黏粒显著正相关(p<0.05)。多因素方差分析结果表明:植被类型、土层深度和土壤类型均对土壤团聚体稳定性有显著(p<0.05)影响。[结论]在两种土壤发育区,退耕后不同植被恢复阶段土壤团聚体稳定性指标均高于耕地,可见退耕还林还草有效提高了土壤团聚体稳定性,增强了土壤抵抗侵蚀的能力,研究结果能为喀斯特区水土保持措施布设和退耕地效益评价提供理论依据。[Objective]The aims of this study are to investigate the effects of cropland fallowing on soil structure and stability in the development areas of yellow and calcareous soils in Qianzhong Karst Region,and to provide theoretical basis for the prevention and control of soil erosion and evaluation of the benefits of revegetation of fallowed cropland in karst region.[Methods]Differential characteristics of soil aggregate composition and stability in shallow(0—30 cm)soil layers of cropland(YM)and different stages of vegetation restoration after fallow〔grassland(CD),scrubland(GC),and woodland(LD)〕were investigated based on the wet-dry sieve method.[Results]The contents of soil mechanical aggregates in the two types of soil development areas decreased with the decrease of particle size,and the content of water stable aggregates decreased at first and then increased with the decrease of particle size,and the main content of soil mechanical aggregates was>1 mm aggregate,and the proportions of yellow loam and lime soil were 82.45%and 84.01%,respectively.The water stable aggregates were mainly>2 mm aggregate,accounting for 53.53%and 54.61%,respectively.The mean weight diameter(MWD)and geometric mean diameter(GMD)of aggregates in yellow soil decreased with the increase of soil depth,while the opposite trend in calcareous soil to that in yellow soil was found.Cluster stability of yellow soil fallow land was better compared to calcareous soils.In general,the MWD and GMD of the two soils were the lowest in YM,and the soil structure damage rate(PAD)was the highest,the stability of soil aggregates in YM was the lowest,and the stability of soil aggregates in different stages of vegetation restoration was improved compared with that in YM.MWD of yellow soil was significantly positively correlated with organic matter content(SOM)and total nitrogen(TN),GMD was significantly positively correlated with SOM,and PAD was significantly positively correlated with silt(p<0.05).MWD and GMD of calcareous soil were significantly positivel

关 键 词：喀斯特 黄壤 石灰土 不同退耕植被 团聚体稳定性 

分 类 号：S152.4[农业科学—土壤学]