Soil pedostructure-based method for calculating the soil-water holding properties

Abstract

Soil aggregates structure (pedostructure) plays a pivotal role in regulating water and nutrient circulation, and consequently defines soil health, productivity, and water use efficiency. However, the soil aggregates structure is not currently considered in the quantification of soil-water holding properties. The authors applied a thermodynamic and soil structure-based approach to quantify soil-water holding properties. The paper provides a methodology, based on pedostructure concept, to quantify field capacity (FC), permanent wilting point (PWP), and available water (AW). The validity of the developed method was tested through application to two types of soil: a loamy fine sand soil and a silt loam soil. The calculated values for FC, PWP, and AW were compared with the FAO recommended values of FC, PWP and AW. For the loamy fine sand, the calculated values were: FC = 0.208 m3/m3, PWP = 0.068 m3/m3, and AW = 0.140 m3/m3 all of which fall within the recommended values of FAO for such a soil type. Similarly, the calculated values for the silt loam were: FC = 0.283 m3/m3, PWP = 0.184 m3/m3, and AW = 0.071 m3/m3 all were in agreement with the FAO recommended ranges for such a soil type. • A thermodynamic, structure-based approach for soil water holding properties.• Unique solutions for quantifying both field capacity and permanent wilting point. © 2018 The Author(s)