The objective of this study was to generate pedotransfer functions (PTFs) to estimate water retention and availability in conventionally-tilled soils and validate some PTFs available in the literature. Disturbed samples were collected from 34 subtropical soil profiles, corresponding to 85 horizons, to determine soil chemical and physical properties and PTFs were generated and validated. The correlations with physical and chemical soil properties were higher for soil water retention at specific tensions (r from 0.36 to 0.92) than for availability (r from 0.13 to 0.66). Water retained at 10, 33, 100 and 1500 kPa tensions may be accurately (i.e. R² > 0.85) estimated by PTFs based on soil chemical and physical properties as predictive variables, but available water capacity may be estimated only with medium or lower accuracy (i.e. R² < 0.85). Of those available in the literature, only PTFs of Giarola et al. (2002) at 10 kPa tension, of Masutti (1997) and of Oliveira et al. (2002) at 33 and 1500 kPa tensions for tropical soils, and of Reichert et al. (2009) at 10, 33 and 1500 kPa tensions for subtropical soils, estimated soil water retention with medium accuracy (i.e. R² from 0.40 to 0.85). These PTFs had R², root mean square error and mean error similar to PTFs that include only particle size distribution and soil organic matter. Further, as was the case for our study, these equations were all generated from a set of soils ranging from low (2:1 type clays) to high weathering (1:1 clays and oxides), thus demonstrating PTFs for hydraulic soil properties are region specific. Finally, none of the PTFs from temperate soils was accurate for estimating water retention in conventionally-tilled soils from subtropical environment, and thus should be replaced by the PTFs from this study.

这项研究的目的是生成pedotransfer函数（PTF），以估计常规耕作土壤中的保水率和有效性，并验证文献中提供的一些PTF。从34个亚热带土壤剖面（对应于85个层位）中收集受干扰的样品，以确定土壤的化学和物理性质，并生成并验证了PTF。在特定张力下，土壤保水率与物理和化学土壤特性的相关性更高（r从0.36到0.92），比可利用性更高（r从0.13到0.66）。保持在10、33、100和1500 kPa张力下的水可能是准确的（即R ² > 0.85）是根据土壤化学和物理特性作为预测变量由PTF估算的，但可用水容量只能以中等或较低的精度估算（即R ²  <0.85）。在现有文献中，只有Giarola等人的PTF。（2002）和Masutti（1997）和Oliveira等人在10 kPa张力下进行了研究。（2002年）在33和1500 kPa张力的热带土壤，和Reichert等。（2009年）在亚热带土壤的张力分别为10、33和1500 kPa的情况下，估计的土壤保水量具有中等精度（即R ²从0.40到0.85）。这些PTF具有R ²，均方根误差和均值误差类似于PTF，仅包括粒径分布和土壤有机质。此外，与我们的研究一样，这些方程式都是从一组低（2：1型粘土）到高耐候性（1：1粘土和氧化物）的土壤中生成的，因此证明了水硬性土的PTF为特定于区域。最后，温带土壤中的任何一种PTF都不能准确估计亚热带环境下常规倾斜土壤中的保水量，因此，本研究中的PTF可以代替。