GENESIS AND CHARACTERISTICS OF SOILS OF THE SANTANAMOUNTAIN RANGE IN THE SERIDÓ REGION, RIO GRANDE DO NORTE, BRAZIL

ABSTRACT Rio Grande do Norte has mountain formations with edaphoclimatic conditions different from those predominating in the state, presenting deeper,acid soils, and milder climate. Among these formations, is the Santana mountain range, which is part of the Serra do Martins Formation. The objective of this work was to interpret the pedogenesis of the representative soils of the Santana mountain range through morphological, physical, and chemical characterizations of soil profiles and evaluate the effect of these attributes on the distribution of pedological forms along the landscape using multivariate analysis. Morphological, physical, and chemical analyses of seven soil profiles of the Santana mountain range were performed. The soils were classified according to the Brazilian Soil Classification System and the data subjected to multivariate analysis. The representative soil classes found were: LATOSSOLO AMARELO Distrófico argissólico; LATOSSOLO AMARELO Eutrófico argissólico; NEOSSOLO QUARTZARÊNICO Órtico típico; NEOSSOLO LITÓLICO Eutrófico fragmentário; NEOSSOLO REGOLÍTICO Eutrófico típico and CAMBISSOLO HÁPLICO Tb Eutrófico léptico. According to the analysis of the morphological attributes, the parent material had great influence on the formation of the different soil classes found in the Santana mountain range. The soil textural classes varied from sand to sandy clay loam. According to the analysis of the chemical attributes, the soil profiles presented acid reaction, great variation of base saturation, and low electrical conductivity. The multivariate analysis established groups of representative soil profiles of the Santana mountain range through the distinction of their physical and chemical attributes, mainly of subsurface diagnostic horizons.

摘要：北里奥格兰德州存在与该州主导土壤气候条件迥异的山地构造，其土壤更为深厚、呈酸性，且气候更为温和。其中的桑塔那山脉隶属于马丁斯山组（Serra do Martins Formation）。本研究旨在通过对土壤剖面的形态、物理及化学特征表征，解析桑塔那山脉代表性土壤的土壤发生学过程，并借助多元分析方法评估这些属性对景观中土壤形态分布的影响。本研究对桑塔那山脉的7个土壤剖面开展了形态、物理及化学分析。供试土壤依据巴西土壤分类系统（Brazilian Soil Classification System）进行分类，并对数据开展多元分析。本次研究发现的代表性土壤类型包括：LATOSSOLO AMARELO Distrófico argissólico（贫腐殖质黏化黄铁铝土）、LATOSSOLO AMARELO Eutrófico argissólico（富腐殖质黏化黄铁铝土）、NEOSSOLO QUARTZARÊNICO Órtico típico（典型正常石英砂质新成土）、NEOSSOLO LITÓLICO Eutrófico fragmentário（富腐殖质碎屑状石质新成土）、NEOSSOLO REGOLÍTICO Eutrófico típico（富腐殖质典型正常冲积新成土）以及CAMBISSOLO HÁPLICO Tb Eutrófico léptico（富腐殖质细粒典型弱育土）。基于形态属性分析可知，母质对桑塔那山脉中不同土壤类型的形成具有显著影响。供试土壤的质地类别范围从砂土至砂质壤土。基于化学属性分析可知，供试土壤剖面呈酸性反应，盐基饱和度差异显著，且电导率较低。多元分析通过区分供试土壤剖面的物理及化学属性（主要为下层诊断层），划分出了桑塔那山脉的代表性土壤剖面群组。