Particle-size distribution models for the conversion of Chinese data to FAO/USDA system.

Wei Shangguan,Yongjiu Dai,Hua Yuan,Carlos García-Gutiérrez

doi:10.1155/2014/109310

Abstract

We investigated eleven particle-size distribution (PSD) models to determine the appropriate models for describing the PSDs of 16349 Chinese soil samples. These data are based on three soil texture classification schemes, including one ISSS (International Society of Soil Science) scheme with four data points and two Katschinski's schemes with five and six data points, respectively. The adjusted coefficient of determination r 2, Akaike's information criterion (AIC), and geometric mean error ratio (GMER) were used to evaluate the model performance. The soil data were converted to the USDA (United States Department of Agriculture) standard using PSD models and the fractal concept. The performance of PSD models was affected by soil texture and classification of fraction schemes. The performance of PSD models also varied with clay content of soils. The Anderson, Fredlund, modified logistic growth, Skaggs, and Weilbull models were the best.

Highlights

Particle-size distribution (PSD) is a basic physical property of soils that affects many important soil properties
The performance of Anderson model (AD) model became better from the T2 scheme to the T3 scheme as one limit (0.25 mm) of PSD is omitted in T3, while the opposite happened to the SELF model
The results from ra2dj values, Akaike’s information criterion (AIC), and geometric mean error ratio (GMER) test indicated that the AD, F4P, F3P, S, and W models had the best performance in three schemes

Summary

Introduction

Particle-size distribution (PSD) is a basic physical property of soils that affects many important soil properties. PSD has been widely used for estimating various soil hydraulic properties [1, 2]. The PSD prediction has been used for comparing and converting texture measurements from different classification systems [3,4,5,6]. Many soil databases do not contain detailed PSD data but contain only several mass fractions and use different cutoff points to separate the size fractions. In the Second National Soil Surveys of China, soil textures were measured by ISSS (International Society of Soil Science) and Katschinski’s systems. The conversion from ISSS and Katschinski’s to the popular USDA (United States Department of Agriculture) system is required to achieve compatibility of soil data and to use pedotransfer functions as estimators of soil hydraulic properties [13, 14]

Objectives

Methods

Results

Conclusion