黄土高原雨水集聚深层入渗(RWCI)系统下山地果园土壤水分时空变异特征

Spatial heterogeneity of soil moisture of mountain apple orchards with rainwater collection and infiltration( RWCI) system in the Loess Plateau,China

水资源短缺是影响黄土高原雨养农业发展的关键性因素,雨水资源开发是缓解该地区水资源短缺的有效措施.本研究利用管式TDR系统监测21年红富士老果园0~300 cm土层土壤含水率变化,分析了雨水集聚深层入渗(RWCI)系统下黄土高原旱作山地果园土壤水分时空分布特征.结果表明:RWCI系统能够显著增加果园土壤含水率,特别是40~80 cm土层(土壤含水率低值区)土壤含水率,在该区域,不同设计深度(40、60和80 cm)RWCI处理(RWCI_(40)、RWCI_(60)和RWCI_(80))年均土壤含水率分别较鱼鳞坑(CK)处理提高75.3%、85.4%和62.4%,分别较裸露坡地(BS)处理提高39.2%、47.2%和29.1%.RWCI_(40)、RWCI_(60)和RWCI_(80)处理土壤水分入渗最大深度分别为80、120和180 cm,显著深于CK处理(60 cm),其中土壤水分变化幅度最大的土层分别主要发生在0~60、0~100和0~120 cm.在果树整个生育期内,RWCI处理土壤平均含水率(0~300 cm)以RWCI_(80)处理最大,其次是RWCI_(40)和RWCI_(60)处理.总体来看,RWCI系统是黄土高原实现雨水资源化和农业高效用水的有效措施.

Water scarcity is a critical factor influencing rain-fed agricultural production on the Loess Plateau,and the exploitation of rainwater is an effective avenue to alleviate water scarcity in this area. This study was conducted to investigate the spatial and temporal distribution of soil moisture in the 0-300 cm under a 21-year-old apple orchard with the rainwater collection and infiltration（ RWCI） system by using a time domain reflectometer（ TDR） probe on the Loess Plateau. The results showed that there was a low soil moisture zone in the 40-80 cm under the CK,and the RWCI system significantly increased soil moisture in this depth interval. Over this depth,the annual average soil moisture under RWCI（40）,RWCI（60） and RWCI（80） was 39.2%,47.2% and 29.1% higher than that of bare slope（ BS） and 75.3%,85.4% and 62.7% higher than that of CK,respectively. The maximum infiltration depth of water under RWCI（40）,RWCI（60） and RWCI（80） was 80 cm,120 cm and 180 cm,respectively,and the soil moisture in the 0-60,0-100 and 0-120 cm was more affected by RWCI（40）,RWCI（60） and RWCI（80）,respectively. Over the whole growth period of apple tree,the maximum value of soil moisture content in the 0-300 cm existed in the RWCI（80） treatment,followed by the RWCI（40） and RWCI（60） treatments. Overall,the RWCI system is an effective meaning of transforming rainwater to available water resources and realizing efficient use of agricultural water on the Loess Plateau.