Abstract:
Pedo-transfer functions are mathematical equations that use basic features describing the soil (e.g. particle size
distribution, bulk density, organic matter content) in order to predict other properties the values of which are not
otherwise available. To predict the physical quality of agricultural soils a pedo-transfer function that uses basic soil
properties (e.g. particle size distribution, dry bulk density, organic matter content) was produced. Evaluation of the soil
physical quality was done by using the S index values. S is a measure of soil structure which controls many of the
physical properties of soils. S index was calculated after using the Arya-Paris model in order to obtain the parameters
from van Genuchten equation that describe the water retention properties of soils. Data analysis from 1923 soil horizons
showed that the S index can be predicted by a single equation from basic soil features, such as clay contents and dry
bulk density values that were taken as independent data variables. A statistically significant multiple linear regression
equation was found and proposed as pedo-transfer function for prediction of the soil physical quality index, S (r2
= 0.41;
p < 0.0001). Pedo-transfer functions are useful solutions for investigation of different aspects of the physical quality of
agricultural soils that do not have readily-available measured data.
