Characteristics of Dried Soil Layers Under Apple Orchards of Different Ages and Their Applications in Soil Water Managements on the Loess Plateau of China

作     者：WANG Yunqiang SHAO Mingan LIU Zhipeng ZHANG Chencheng 

作者机构：State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Chinese Academy of Sciences & Ministry of Water Resources Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences 

出 版 物：《Pedosphere》 (土壤圈（英文版）)

年 卷 期：2015年第25卷第4期

页      面：546-554页

核心收录：

学科分类：09[农学] 0902[农学-园艺学] 090201[农学-果树学] 

基　　金：supported by the National Natural Science Foundation of China (No. 41471189) the Youth Science and Technology New Star Foundation of Shaanxi Province, China (No. 2013KJXX-09) the CAS "Light of West China" Program the Youth Innovation Promotion Association CAS 

主　　题：deep soil growth age plant roots soil desiccation soil water content soil-plant water relation 

摘      要：Negative soil water balance （i.e., water input 〈 water output） can lead to soil desiccation and subsequently the occurrence of a dried soil layer （DSL）. The DSLs are generally studied at a specific sampling depth （e.g., 500 cm）, and the actual extent of DSLs remains unknown due to the challenge of collecting deep soil samples. To investigate the characteristics of actual DSLs under different ages of apple orchards and ascertain the optimal age of apple orchards for avoiding/controlling the formation of DSLs, soil samples were collected to a depth of 1800 cm under apple orchards of different ages in Changwu on the Loess Plateau of China. As the ages increased, soil water content （SWC） and mean SWC in DSLs showed an overall decreasing trend, whereas while DSL thickness and the quantity of water deficit （QWD） in DSLs demonstrated an increasing trend. The DSL was the thickest （1 600 cm） under the 17-yeax-old orchard, the forming velocity of DSL thickness was the highest at the apple tree growth stage of 9-17 years （168 cm year-l）, and the highest increasing velocity of QWD （-181 mm year-1） was also observed at this stage. The thickness of DSL was significantly correlated with growth age and root depth of apple trees （r 〉 0.88）, whereas the QWD and mean SWC in DSLs were found to have no correlation with them. The optimal age of apple orchards for avoiding/controlling the formation of DSLs was about 9 years. This information provided pertinent references for the management of deep water resources by controlling the growth age of plants. Key Words： deep soil, growth age, plant roots, soil desiccation, soil water content, soil-plant water relation.