基于Gardner模型的黔西南土壤水分特征分析

Water Retention Characteristics of Typical Soils in Southwestern Guizhou Province

【目的】了解黔西南州不同地区土壤剖面(0~60 cm)持水特性的差异。【方法】在实验室内利用压力膜仪法测定了各土壤的水分特征曲线,并分析其土壤水分特征。【结果】黔西南州各植烟县不同土层土壤水分特征曲线匀可采用Gardner模型拟合,不同烟区土壤水分常数及持水特性有明显差异。其中兴义、贞丰、安龙和普安土壤持水性能强弱表现为40~60 cm>20~40 cm>0~20 cm,晴隆和兴仁烟区土壤持水性能表现为20~40 cm>40~60 cm>0~20 cm;各植烟县烟田0~20 cm土层土壤持水性强弱顺序为兴义,安龙,晴隆,贞丰,普安和兴仁;20~40 cm土层土壤的持水性强弱顺序为兴义,安龙,晴隆,兴仁,贞丰和普安;40~60 cm土层土壤的持水性强弱顺序为兴义、安龙、普安、晴隆、贞丰和兴仁。【结论】同一植烟县深层土壤持水能力强于表层土壤,不同植烟县间的土壤持水性也存在明显差异。

[Objective] Water retention characteristics is a soil quality indicator, and this paper presents the water retention curves measured from typical soils in southwestern Guizhou Province. [Method] Soil samples from 0- 60 cm were taken from tobacco fields and their water retention curves were measured in laboratory using pres- sure membrane apparatus. [Result] All measured water release curves can be fitted to the Gardner formula but the model parameters varied. Overall, the water-holding capacity of the subsoil is higher than that of the top soil. For soils in Xingyi, Zhenfeng Anlong and Puan, their water-holding capacity at different depths was ranked in 40- 60 cm〉20-40 cm〉0-20 cm, while for soils in Qinglong and Xingren, it was in the order of 20-40 cm〉40-60 cm〉0-20 cm. Spatially, the water holding capacity of soils in 0-20 cm and 20-40 cm ranked in Xingyi〉Anlong〉Qin-glong〉Zhenfeng〉Puan〉Xingren, while of the soil in 40-60 cm was order in Xingyi〉Anlong〉Qinglong〉Xingren〉Zhenfeng〉Puan. [Conclusion] The water retention characteristics are spatially variable and the results presented in this paper can be used as refences in designing irrigation schedules for this region.