黄土区果农复合系统种间水分关系研究

Research on Soil Moisture Relations Among Types of Agroforestry System in the Loess Region

选择黄土区7种典型果农复合类型,进行野外实验布设。利用土钻取样和烘干称重法进行土壤含水量的测定,研究了不同果农复合类型土壤水分含量的水平方向变化与垂直剖面变化规律,分析了黄土区果农复合类型种间水分竞争关系。研究表明,在水平方向上,果农复合类型土壤水分含量的变化与林带的方位、距离有关,果农复合对水分竞争并不显著,树木对光遮蔽作用的强弱,才是影响土壤水分水平变化的主要因素。在垂直方向上,根系对土壤水分的竞争区域主要在0—60 cm土层范围内。同单作作物土壤水分的比较得出,苹果和其它农作物的复合有助于土壤水分的保持;核桃、桃与其它农作物的复合,则表现为不同的影响,即对玉米的协助大于竞争,对花生的竞争大于协助。

Seven typical compound types of fruit tree and crops in the loess region were selected and soil moisture was tested by the traditional weighing method to find out the relations of soil moisture affected by the compound types in horizontal and vertical directions. Results indicated that soil moisture for the compound types was related to the orientation and distance from the shelterbelt in horizontal direction. The competition between fruit tree and crops was not significant. Soil moisture was mostly influenced by the intensity of shading light. The main competition layer of roots for soil moisture was within 60 cm of soil surface in vertical direction. The comparison with soil moisture for the single crop indicated that compound types of apple tree and other crops helped to maintain soil moisture. The compound types of walnut, peach, and other crops had different effects on soil moisture. More assistance to corn was observed rather than competition and more competition to peanut was found rather than assistance.