黄土高原沟壑区塬面苹果园土壤水分特征分析

Study on Characteristics of Apple Orchard Soil Moisture in Gully Region of Loess Plateau

为了解长期种植果树对黄土高原沟壑区土壤水分的影响,对不同种植年限的塬面果园土壤水分特征进行了分析。结果表明：黄土沟壑区塬面果园土壤水分含量普遍低于80%田间持水量,水分较亏缺。0~10 m果园土壤平均含水量与3 m以下各层含水量均呈极显著相关关系,与2~3 m层含水量呈显著相关关系,与0~2 m层次的土壤含水量相关性不显著。土壤水分含量随种植年限的增加呈现先降低后又略有恢复的趋势,但水分恢复量不大。土壤水分波动性及其亏缺量随种植年限的增加呈现先增加后减小的抛物线型变化趋势。果树根系所吸收利用的土壤水分的深度,随着种植年限的增加而增深。在果树的主要生命周期内,其吸收利用的土壤水分最大深度可达8 m上下,耗水量最大时期为盛果中期（种植15年左右）。

In order to understand how apple trees influence the orchard soil moisture,the characteristics of orchard soil moisture under different planting-year were investigated.The results showed that the orchard soil moisture in gully region of Loess Plateau was deficient for it was generally lower than the 80% of field capacity.The average soil water content at 0-10 m depth had extremely significant correlation with those of the layers below 3 m,had significant correlation with that of the 2-3 m layer,but had no correlation with that of 0-2 m depth.With the increase of planting-year,soil water content decreased firstly and then increased,soil water volatility and the quantity of water deficit increased firstly and then decreased,the water depth available to the roots deepened.The deepest water depth available to the roots could reach to 8m during the lifecycle of apple trees,