RETENTION CURVES AND AVAILABLE WATER CAPACITY IN LATOSOLS

ABSTRACT Water stored in the soil between field capacity and the permanent wilting point, is known as the available water capacity. Its availability to be effectively used by plants depends on the type of soil and its water retention characteristics. The aim of this work was to compile information about water retention curves in Latosols, and to provide a first approximation of values and most likely amplitudes for water storage and available water capacity of these soils. The database was constituted from information collected from articles, theses, dissertations and other publications. Soil water retention curves, as well as available water, were estimated for the order Latosols, and for the suborders Red Latosol (RL), Red-Yellow Latosol (RYL) and Yellow Latosol (YL). RL presented the lowest amplitude of water storage between field capacity and permanent wilting point, resulting in lower available water capacity compared to Yellow and Red-Yellow Latosols. YL presented the highest available water capacity among analyzed soils.

摘要：田间持水量（field capacity）与永久萎蔫点（permanent wilting point）之间储存在土壤中的水分，被定义为有效持水量（available water capacity）。该部分水分可供植物有效利用的程度，取决于土壤类型及其持水特性。本研究旨在汇编砖红壤（Latosols）的持水曲线（water retention curves）相关资料，并首次估算此类土壤的储水量及有效持水量的数值与最可能波动范围。本数据库的资料来源于期刊文章、学位论文及其他公开出版物。研究针对砖红壤土纲及其下属的红砖红壤（RL）、红黄砖红壤（RYL）与黄砖红壤（YL）三个亚类，分别估算了其土壤持水曲线与有效持水量。其中，红砖红壤在田间持水量与永久萎蔫点之间的储水波动范围最小，其有效持水量低于黄砖红壤与红黄砖红壤；在所分析的全部土壤样本中，黄砖红壤的有效持水量最高。