加格达奇市黄芪种植地土壤形态描述及适宜性分析

黄芪(Astragalus membranaceus)因其药用价值高近年来被大量、无节制采挖,致使野生黄芪资源几近枯竭。探究黄芪适宜生长的土壤,将为人工驯化黄芪提供一定的科学依据。本研究以加格达奇市连续多年人工种植黄芪的土壤为研究对象,系统分析了2个典型土壤剖面的形态特征及土壤养分。结果表明：表层土壤结构疏松,孔隙度较大,土壤颜色较深,干态为黑棕色,润态为黑色;淀积层及母质层土壤结构坚实,孔隙度较小,土壤颜色随着层次加深,颜色逐渐变黄、变棕。表层土壤质地肥沃,多以壤土为主;表层有机质含量高,分别为122.07、110.09 g/kg,占其整个土壤剖面有机质含量的52%和82%,土壤剖面有机质随土层深度的增加呈现一个骤降的趋势;表层土壤全氮含量较高,分别为6.58、8.87 g/kg,而土壤全磷含量较低,主要分布于土壤表层,表层土壤的全磷含量分别为0.07、1.01 g/kg,土壤酸碱度在pH 5.11~6.35之间。黄芪适应生长土壤质地疏松,土壤温度状况为寒冻性、土壤水分状况为湿润,土壤肥沃,表层土壤有机质含量高,全氮含量也较高,而全磷含量较低,土壤呈弱酸性至中性。

The Morphological Description and Suitability Analysis of Soils Planted with Astragalus membranaceus in Jiagedaqi City

Due to its high medicinal value, Astragalus membranaceus has been dug intensively and unrestrainedly in recent years, resulting in the near exhaustion of the resources. Exploring the suitable growth soil of Astragalus membranaceus could provide a theoretical basis for its artificial cultivation. In this study, the soil planted with Astragalus membranaceus for many years in Jiagedaqi City was taken as the research object. Morphological characteristics and soil nutrients of the typical soil profiles were analyzed. The results showed that the structures of surface soil were loose, the porosities were large and the colors were darker, which were dark brown in dry state and black in wet state. The deposition and parent material layers were solid, the porosities were small, and the soil colors gradually turned to yellow and brown with the increase of soil depth. The surface soil was fertile, with mainly loam textures and high organic matter contents, which were 122.07 and 110.09 g/kg, respectively. Organic matter contents in surface layer accounted for 52.0% and 82% of total organic matter content in the soil profile, respectively. Organic matter contents in the soil profiles showed a dramatic drop trend with the increase of soil depth. Total nitrogen contents in the surface layer were relatively high, which were 6.58 and 8.87 g/kg, respectively, but total phosphorus contents of the soil were relatively low, which were 0.07 and 1.01 g/kg, respectively, in the surface layers. The pH of the soil was between 5.11 and 6.35. The soil suitable for Astragalus membranaceus growth was with loose textures, frosty temperature condition, wet moisture condition and fertile, and with high soil organic matter contents, high total nitrogen contents, but low total phosphorus contents in the surface soil, and the pH value was weak acidity to neutrality.