Study on Cryerts in North Songnen Plain, China | 松嫩平原北部寒变性土的研究

Chinese. 摘　　要：2008年在黑龙江省松嫩平原北部的北安市（47.53°N,126.16°E）和依安县（47.45°N,125.13°E）所在的乌裕尔河阶地上的寒均腐土地区,进一步观察了7个土壤剖面,发现其中有3个剖面具有变性特征。其母质有第四系中更新世（Qp2）黄土性冲-湖积物,和白垩系的泥页岩风化物（K2）。诊断特征：全剖面黏粒（〈2μm）含量330～480 g.kg-1;心土层棱柱状结构破碎成棱块状;可见楔形结构,或滑擦面;旱季土壤开裂,冻融期和雨季闭合。线膨胀系数可高达0.19 cm.cm-1,土壤代换量在34～37 cmol.kg-1之间。黏土矿物以伊蒙混层、蒙皂石为主,控制层段的蒙皂石总量约占66%～70%。按美国土壤系统分类检索,符合变性土纲的鉴定标准,将其划归寒变性土亚纲（Cryerts）,其中土类有简育寒变性土（Haplocryerts）,亚类有典型简育寒变性土（Typic Haplocryerts）和艳色简育寒变性土（Chromic Haplocryerts）。研究认为,本地的寒变性土主要是由于原母质和某些寒均腐土的心土层累积了大量膨胀性的伊蒙混层和蒙皂石黏土矿物,在干湿交替的气候和加速土壤侵蚀等综合因素影响下,土壤变性土化作用日趋明显,已危及民房和路基的稳定性。

English. To explore whether Vertisols are formed in higher latitude areas where soils are in eryic temperature regime, seven soil pedons were studied in Bei＇an （47.53 ° N, 126.16° E）and Yi＇an （47.45 °N, 125.13°E）. It is located at the terraces of Wu-Yu-Er River in northern Heilongjiang Province, Songuen Plain, China in 2008. Three soil padons among the 7 were identified as Vertisols based on the soils clay（ 〈2 μm）content（330-480 g・kg. 1） and unique struetures/slinksides, and cracks that open in dry spring and autumn. They close when soil moisture is high in the raining season and during soil de-frenzied period. The three pedons found possess a great amount of smecite and mixed smecite and illite at surface and subsoils. The total smecite is from 66% to 70%. Therefore,the phenomena of soil movement were observed from the profiles and COLE is averagely 0. 14 cm. cm. l, the highest reaching to 0.19cm・cm. 1According to USDA＇ s Keys to Soil Taxonomy （ 2010 ）, the three soil pedons are classified as Typic Haplocryert and Chromic Haplocryerts. Other pedons belong to Vertie Isohumosols （Vertic Phaeozems ） , or regular Phaeozems. The Cryerts are formed by inheriting the clay and expensive clay minerals from Vertic Isohumosols as well as from weathered products of clay rocks and alluvial-lacustrine （Qp2）. This occurs under a climate with alternative dry and wet seasons also with a very cold winter. The formation of the Cryerts here is one of the indicators of degradation of the Phaeozems influenced by top soil erosion. The damage of light structures and transportation systems were observed.