HYDRAULIC CONDUCTIVITY AND DIFFUSIVITY AS CALCULATED FOR WATER FILLED PORES IN CULTIVATED CLAY SOILS

Amer, Abdelmonem M.; DeTar, William; El-Sharkawy, Amal F.

doi:10.21608/mjae.2014.98898

HYDRAULIC CONDUCTIVITY AND DIFFUSIVITY AS CALCULATED FOR WATER FILLED PORES IN CULTIVATED CLAY SOILS

Document Type : Original Article

Authors

¹ Soil Science Dept., Faculty of Agriculture, Menoufia University, 32511Shebin EI-Kom, Egypt.

² 17053 Shafter Avenue, Shafter, CA 93263, USA

³ Agricultural Engineering Institute, Ministry of Agriculture, Dokki, Giza, Egypt.

10.21608/mjae.2014.98898

Abstract

The aim of this study was to propose equations to estimate unsaturated hydraulic conductivity, K(θ)[LT^--1],, water diffusivity, D(θ) [L²T^-1], intrinsic permeability, k [L² ] and water flow, ,q[L³T^-1 ] in plant-root zone. Also an equation for predicting so called potential conductivity of soil water filled pores Kp(θ) [M L^-1T^-3] (erg. cm^-3.sec^-1 or joule. m^-3 sec^-1) was derived for each pore size class. Three alluvial clay soils located at middle and northern Nile Delta were used to apply the assumed equations. The first soil was uncultivated and the other two soils were cultivated with cotton yield during 2009 season. The soil profiles were different in their salinity, clay % and source of irrigation water. The equations which assumed to predict soil water movement parameters considered only the matric potential as a driving force in capillary pores, and gravitational potential that is critical for the large, non-capillary pores. Data of pore size distribution were obtained for the investigated soil profiles using water retention data. The calculated K(θ), D(θ) and k values were conformable to the common measured ranges, indicating the applicability of the proposed equations for predicting water movement parameters in agricultural clay soils.

Keywords

References

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