植物营养与肥料学报2015,21(3）：694-701 Jourmal of Plant Nutrition and Fertilizer
doi:10.11674/zwyf.2015.0316 http: //www.plantnutrifert.org
渭北果园土壤物理退化特征及其机理研究
魏彬萌，王益权
（西北农林科技大学资源环境学院，陕西杨凌712100）
摘要：【目的】针对我国渭北苹果主产区出现的随植果年限增加，果园土壤质量严重退化，树势衰弱、树体过早衰老、抗性降低、腐烂病及早期落叶病频繁发生，果品产量与品质下降等间题，开展了渭北苹果园土壤物理质量退化特征、退化机理及危害程度等问题的研究，以期查明制约果业可持续发展的因素，为果园土壤科学管理提供依据。【方法】在渭北黄土源区选取了<10a、10～20a、>20a3个园龄段果园各4个，并以土壤条件相同的农田作对照，在果树冠层投影范围内距树干2/3处采取土样，测定土壤剖面不同层次容重、紧实度、孔隙度、饱和导水率、粘粒含量等物理性指标。【结果】渭北果园土壤容重和紧实度随园龄和土层深度的增加而增大，尤其在表层(20cm）以下，土壤容重已经达到了1.45→1.61g/cm，紧实度达到933～2433kPa，严重超出果树健康生长的阔值。土壤孔
度仅在0—20cm土层能够保持在50%以上，属于良好状态，面20
m土层维持在40%～46%，已处于紧实和
严重紧实状态。土壤饱和导水率在果园表层和紧实层均表现出随植果园龄的增大而减小的趋势，尤其是10～20a 和>20a的果园亚表层土壤饱和导水率低至46.88cm/d和20.89cm/d，制约着降水人渗和土壤摘。3个园龄段果园土壤剖面上粘粒含量随土层深度呈递增趋势，且在0—30cm土层随园龄的增加面明显减少，而在30cm以下则随园龄的增加而呈递增趋势。进一步分析发现，粘粒含量与土壤容重、紧实度以及孔隙度之间呈极显著的相关关系。以压实密度（PD）为指标，对渭北果园土壤压实程度进行评估，发现渭北果园20cm土层以下的土壤压实密
果园20cm以下的亚表层土壤孔隙密实、容重和紧实度增大，土壤饱和导水率递减是其土壤物理性质退化的主要特征，表层土壤粘粒的深层移动与淀积是土壤物理退化的主要过程和机理，果园土壤翻耕扰动少、对物理退化干预
少是其土境物理退化程度逐渐加剧的外在原因，土壤团聚体稳定性差是土壤物理状态退化的根本原因。关键词：苹果园土壤；物理退化；容重；紧实度；饱和导水率
中图分类号：S152.5；S606*.1
文献标识码：A
文章编号：1008505X(2015)03069408
Physicaldegradationcharacteristicsandmechanism
oforchardsoilinWeibeiRegion
WEI Bin-meng, WANG Yi-quan
(College of Resources and Enxironmental Sciences, Northaest A&F Unitersity, Yangling, Shaanxi 712100, China)
Abstract: [Objectives] Apple production contributes to the economy in Shaanxi province greatly. But soil quality of the orchard land has degradated greatly after years of fruit production. That may has led to many issues such as trees weakening, fast aging and reduced resilience. Specifically the apple tree valsa canker and leaf defoliation diseases occur more frequently, and fruit yield and quality decreases greatly. The objective of this study was to investigate the characteristics, mechanism and degree of soil physical degradation in different aged orchards, to provide scientific basis for orchard soil management and eventually to improve the yield and quality of apple production. [Methods] Four replicates of < 10, 1020 and > 20 - year old orchards were selected for the study. Soil samples within two-thirds of the radius of the tree canopy projection to the trunk were taken. Soil samples were used to measure physical properties such as soil bulk density, compaction, porosity, saturated
收稿日期：2014-04-09
接受日期：2014-11-16
网络出版日期：2015-01-27
基金项目：陕西省农业厅项目"陕西苹果土壤与施肥标准化管理技术研究"资助。
作者简介：魏彬萌（1989—），女，陕西成阳人，硕士研究生，主要从事土壤质量方面的研究。E-mail；442516031@qq-com
*通信作者 E-mail;soilphysics@163.com
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