晋陕峡谷河流阶地枣林土壤水分有效性及干燥化分析

选取晋陕峡谷河流阶地枣林土壤作为研究对象，采用土壤水分有效性指标A_w、土壤干燥化强度指数（SDI）等，定量研究河流阶地0~500 cm土层土壤水分有效性及干燥化的空间差异。结果表明：不同阶地土壤水分有效性A_w具有显著性差异（P<0.05），一级阶地（0.36）显著高于二级（0.08）和三级（0.14）阶地。不同深度土壤水分有效性差异为：0~200 cm土层土壤，除60~100 cm土层外，各层一级阶地显著高于二级、三级阶地（P<0.05）；110~300 cm、310~500 cm土层土壤水分有效性分别表现为一级阶地最低（最大值-0.06）和最高（最大值1.04）的水分状况(P<0.05)。对土壤水分有效性分级，一级阶地多处于无效水和富余水状态，二、三级阶地多处于难效水状态。200~500 cm土层土壤平均干燥化强度为：三级阶地（69.87%）>二级阶地（69.23%）>一级阶地（-24.78%）。综合考虑土壤水分相关指标及植被生长规律,河流三级阶地更适合枣树生长，而一级、二级阶地需加强灌溉管理，并增加适当的农艺措施才能满足枣树的正常生长发育条件。

An analysis on soil moisture availability and dryness of jujube forest in River Terrace of Jinshaan Valley

The soil of jujube forest on river terraces in Jinshaan Valley was selected as the research object. The soil water availability index (A_w) and the soil drying intensity evaluation method (SDI) were used to quantitatively study the soil water availability and spatial drying difference of 0~500 cm river terrace. The results showed that, there was a significant difference in soil water availability between different terraces (P<0.05). The first terrace (0.36) had significantly higher A_w than the second terrace (0.08) and the third terrace (0.14) did. The significant difference of soil water availability in different depths was: in 0~200 cm soil except 60~100 cm, the first terrace of each layer was significantly higher than the second and third terrace (P<0.05); the lowest (maximum value: -0.06) and the highest (maximum value:1.04) water status of the first terrace were shown in 110~300 cm and 310~500 cm, respectively (P<0.05). For the classification of soil water availability, the first terrace was mostly in the state of invalid water and surplus water, and the second and third terraces were mostly in the state of less available water. The average drying strength of 200~500 cm soil was as third terrace (69.87%) >second terrace (69.23%) > first terrace (-24.78%). Considering the soil moisture index and the law of vegetation growth, this paper holds that the jujube trees grew more easily in the third terrace of the river, while the first and second terraces needed to strengthen irrigation management and increase agronomic measures to suit the normal growth and development of jujube.