陕西关中土垫旱耕人为土样区的基层分类研究

选择陕西关中土垫旱耕人为土地区为样区,以该地区代表性土壤土垫旱耕人为土(土)为研究对象,在野外调查、室内分析及查阅大量有关剖面资料的基础上,根据中国土壤系统分类体系,对土垫旱耕人为土(土)的基层分类进行了研究。研究表明,应用土壤颗粒大小级别、矿物学型和土壤温度状况等3项指标对土族进行划分,在0~160cm的控制层段中小于2mm的土壤平均质地,多数剖面为粘壤土,少数为壤土或砂质壤土,矿物学型属伊利石型、伊利石混合型或蛭石型,土壤温度属温性或温热土壤温度状况。土垫旱耕人为土(土)土系的控制层段拟定为从表土层上界向下160cm,对于诊断层的底部在160cm以下的,则从表土层至诊断层的下部边界,特征土层有肥熟表层、土垫表层、暗沃表层、耕作淀积层、粘化层、粘质层、CaCO3高度淀积层、CaCO3中度淀积层、CaCO3低度淀积层、氧化还原层和稚育层。根据样区9个典型剖面,结合关中地区土垫旱耕人为土(土)的有关研究资料,划分了土族和土系,并描述了各土系的典型特征及土系间的变异情况。

BASIC SOIL CATEGORIES OF EARTH-CUMULIC ORTHIC ANTHROSOLS AREA IN GUANZHONG, SHAANXI PROVINCE

Through field survey,lab analysis and reference to large volumes of soil profile data,study on basic soil taxonomy of Earth-cumulic Orthic Anthrosols (Lou soil) was carried out in Guanzhong,Shaanxi Province. Soil classification was made at the soil family level based on particle composition,soil mineral composition and soil temperature. Of the profiles with the control sections (0 to 160 cm) of soil <2 mm,the majority were of clay loam,and the minority of loams or sandy loam in texture. The soils were dominated with illite,mixed illite or vermiculite in mineral composition and mesic or low-thermic in soil temperature. The control section of the soil series was defined to be from the top of surface horizon down to 160 cm in depth or to the bottom of the diagnostic horizon when the bottom of the diagnostic horizon exceeds 160 cm in depth. The diagnostic horizon had 11 characteristic horizons,i. e. Fimic epipedon,Earth-cumulic epipedon,Mollic epipedon,Agric horizon,Argic horizon,Weak-argic horizon,Intensive-calcic horizon,Medium-calcic horizon,Weak-calcic horizon,Redoxic horizon and Weak-cambic horizon. Based on the data of the 9 profiles and other related data of Earth-cumulic Orthic Anthrosols (Lou soil),the soils could be sorted into 9 soil families and 9 soil series. Typical characteristics of the soil series and differences between the series were described.