不同土地利用方式砖红壤团聚体水稳性及其对前期含水率的响应  

Response of Water Stability of Lateritic Aggregates with Different Land Use Types under Different Antecedent Moisture Content

作　　者：王杰 任少聪 魏玉杰[1] 黄伊静 阳邦戈 蔡崇法[1] WANG Jie;REN Shaocong;WEI Yujie;HUANG Yijing;YANG Bangge;CAI Chongfa(College of Resource and Environment,Huazhong Agricultural University,Wuhan 430070,China)

机构地区：[1]华中农业大学资源与环境学院,武汉430070

出　　处：《土壤学报》2024年第4期978-988,共11页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(42077067,42277329)资助。

摘　　要：前期含水量是影响土壤团聚体稳定性的重要因素,而其对砖红壤结构稳定性的影响缺乏系统研究,本文以海南地区3种典型利用方式(林地、荒地、耕地)下玄武岩发育砖红壤团聚体为研究对象,测定其理化性质,干、湿筛团聚体组成及不同前期含水率(3%、5%、10%、15%、20%)条件下3~5 mm粒径团聚体破碎后粒径分布状况,采用冗余分析探究了土壤性质及前期含水率对不同土地利用方式砖红壤团聚体水稳性的影响。结果表明:(1)不同土地利用方式下,土壤部分性质存在显著差异,如土壤pH、有机碳、阳离子交换量及部分交换性盐基离子等,其余性质差异较小。(2)土壤水稳性团聚体组成总体呈现“单峰”或“双峰”分布,峰值主要出现在2~1 mm和0.5~0.25 mm处,对于表层土壤而言,林地土壤团聚体稳定性最高,而耕地土壤团聚体稳定性较弱,表下层土壤稳定性显著(P<0.05)低于表层土壤。(3)在风干条件下,表层土壤团聚体水稳性普遍较高(WSA>90%,MWD>1.5,GMD>1.2),随着前期含水率的增加,团聚体破碎后大团聚体(>2 mm)含量有不同程度的变化,整体呈现水稳性大团聚体含量随前期含水率增加而增加。(4)土壤有机碳是影响砖红壤团聚体水稳性的最主要因素,其对团聚体水稳性差异的解释率达80.6%。【Objective】Antecedent moisture content is a critical factor affecting soil aggregate stability.However,its influence on the aggregate stability of lateritic soils developed from basalt has not been systematically investigated.To unravel the intricate interplay between soil properties,antecedent moisture content,and the water stability of lateritic soils developed from basalt,a meticulous investigation was undertaken.This study delved into the diverse land use types,aiming to shed light on the intricate relationship between these factors and aggregate water stability.【Method】In the latosol region of Hainan,a comprehensive study was conducted to examine the influence of three prevalent land use types,forest,cropland,and wasteland,on the soil properties and aggregate size distribution.Through a preliminary investigation,the tested soils were meticulously analyzed.The LB method,specifically the Fast Wetting variant,was employed to determine the aggregate size distribution within the 3-5 mm range across the various land use types.This assessment was performed under five distinct antecedent moisture contents of 3%,5%,10%,15%,and 20%.Subsequently,water stability indices,including Water Stability Index(WSA),Mean Weight Diameter(MWD),and Geometric Mean Diameter(GMD),were meticulously calculated to provide valuable insights into aggregate water stability.【Result】Distinctive variations in soil properties,encompassing pH,organic carbon,cation exchange capacity,and some exchangeable base cations,were prominently observed across different land use types.The distribution of water-stable aggregates in the lateritic soil exhibited either an unimodal or bimodal pattern,with peaks predominantly observed at 2–1 mm and 0.5–0.25 mm size fractions.Notably,forest soils displayed the highest aggregate stability among surface soils,while cultivated soils exhibited relatively weaker aggregate stability.Furthermore,subsurface soils demonstrated significantly lower aggregate stability(P<0.05)compared to surface soils.When con

关 键 词：砖红壤 土壤结构 前期含水率 团聚体水稳性 

分 类 号：S154.27[农业科学—土壤学]