基于微结构量化的枣园根土复合体各向异性试验

Experiment on Anisotropy of Soil-Root Composite Based on Microstructure Quantification

摘要:

为确定南疆枣园切根抚育作业工艺，测定了枣园土壤含水率、坚实度、孔隙度、容重、粒径分布等物理参数，统计了枣园待切根区的根系聚集深度、土壤含根量等，确定了切根区位置为距树干750mm和切根作业深度应在0～200mm范围内可调的农业技术要求。研究结果表明，根土复合体具有各向异性，取样角θ为0°、45°、90°时，根土复合体抗剪强度T关系为T0°＜T45°＜T90°。为分析根土复合体产生各向异性现象的原因，采用扫描电镜（SEM）获取了根土复合体在不同取样方向上的微观结构图像，通过PCAS软件处理并获取了根土复合体微观结构参数。将根土复合体的宏观图像、微观图像、微观结构参数、抗剪强度参数结合，定性和定量分析了根土复合体产生各向异性的原因及规律，得到微观结构参数与抗剪切强度相关性由强到弱依次为孔隙概率熵、孔隙形态分维数、颗粒形状系数、孔隙形状系数、颗粒概率熵、颗粒形态分维数。根据研究结果提出根土复合体抗剪强度测定时，环刀应垂直于耕作过程产生的实际剪切发生面方向取样。本研究可为枣园切根抚育机具设计和研发提供理论依据，为土壤耕作类部件优化设计、耕作类部件与土壤相互作用关系等研究提供参考。

Abstract:

To determine the operation technology of root cutting and nurturing in jujube orchards in southern Xinjiang, physical parameters such as soil moisture content, solidity, porosity, bulk density, and particle size distribution were measured. The root aggregation depth and soil root content of the jujube orchard’s root cutting area were also calculated. The agricultural technical requirements were determined that the root cutting area should be located 750mm away from the tree trunk and the depth of the root cutting operation should be adjustable within the range of 0~200mm.The research results indicated that the root soil composite had anisotropy. When the sampling angles θ were 0°, 45° and 90°, the shear strength T relationship of the root soil composite showed trend of T0°