Impact of Simulated Irrigation with Treated Wastewater and Saline-Sodic Solutions on Soil Hydraulic Conductivity, Pores Distribution and Fractal Dimension

Irrigation with treated wastewater which has the characteristics of higher salt content, larger sodium adsorption ratio (SAR), and more organic matter and suspended particles can cause the deterioration of the soil environment. Ordinary water, treated wastewater, and saline-sodic solutions with SAR = 3, 10 and 20 (mmolc·L− 1)0.5, respectively, were used as five irrigation water types, and the changes of soil saturated hydraulic conductivity (K s), soil pores distribution, and soil pores single fractal dimension (D m) were studied after simulated irrigation for 1 and 2 years with simulated irrigation systems, which consisted of soil bins and simulated evaporation systems. The results showed that soil K s in the following descending order: CK > SAR3 > WW > SAR10 > SAR20, and the adverse effects on soil K s caused by suspended solid particles and dissolved organic matter might play a more significant role than sodium in treated wastewater. The 0-5 cm soils had a smaller single soil pore area but larger pores quantity after simulated irrigation, the distribution of soil pores which was irrigated with treated wastewater had a smaller change compared with saline-sodic solutions treatments, and it showed the soil pores structure binary image was an effective method to analysis soil pores distribution. Soil D m increased after simulated irrigation, and the smallest was the soil simulated irrigation with treated wastewater for 1 year, because the plugging and filling of suspended particles and dissolved organic matter in treated wastewater made the soil pores well distributed, but the soil D m did not increase with increasing of SAR levels in irrigation waters. The relative SAR levels irrigation to soils and soil K s had a good linear correlation relationship, while the relationship between soil D m and the relative SAR levels irrigation to soils was very complicated. The soil D m which calculated from soil binary images could not well reflect the hydraulic conductivity of saturated soil. Irrigation with treated wastewater had a greater effect on soil K s than soil D m, comparing with saline-sodic solutions which had the similar SAR value. It was suggested that the future research should consider both the horizontal and vertical directions of soil D m to well reflect the soil K s.

[1]  Yaohu Kang,et al.  Soil salinity management with drip irrigation and its effects on soil hydraulic properties in north China coastal saline soils , 2012 .

[2]  Benoit B. Mandelbrot,et al.  Fractal Geometry of Nature , 1984 .

[3]  Ouyang Zhiyun,et al.  Micromorphology of macromolecular superabsorbent polymer and its fractal characteristics , 2009 .

[4]  B. Mandelbrot,et al.  Fractal character of fracture surfaces of metals , 1984, Nature.

[5]  Ana M. Tarquis,et al.  Multifractal analysis of the pore- and solid-phases in binary two-dimensional images of natural porous structures , 2006 .

[6]  Antonio Saa,et al.  Fractal and multifractal analysis of pore-scale images of soil , 2006 .

[7]  Guangdi Li,et al.  The effects of stubble retention and tillage practices on surface soil structure and hydraulic conductivity of a loess soil , 2011 .

[8]  Edith Perrier,et al.  Generalizing the fractal model of soil structure : the pore-solid fractal approach , 1999 .

[9]  Matthias C. Rillig,et al.  Are power laws that estimate fractal dimension a good descriptor of soil structure and its link to soil biological properties , 2011 .

[10]  R. K. Gupta,et al.  Effect of high salinity and SAR waters on salinization, sodication and yields of pearl-millet and wheat , 1992 .

[11]  J. W. Crawford,et al.  Integrating processes in soils using fractal models , 2000 .

[12]  Hans-Jörg Vogel,et al.  Topological characterization of pore space in soil — sample preparation and digital image-processing , 1996 .

[13]  Y. P. Singh,et al.  Changes in hydraulic conductivity of soils varying in calcite content under cycles of irrigation with saline-sodic and simulated rain water , 1999, Irrigation Science.

[14]  Gaspare Viviani,et al.  Wastewater Reuse Effects on Soil Hydraulic Conductivity , 2004 .

[15]  A. Mahdy,et al.  Soil Properties and Wheat Growth and Nutrients as Affected by Compost Amendment Under Saline Water Irrigation , 2011 .

[16]  Gerhard Gerold,et al.  The surface fractal dimension of the soil–pore interface as measured by image analysis , 2001 .

[17]  Scott W. Tyler,et al.  Application of Fractal Mathematics to Soil Water Retention Estimation , 1989 .

[18]  Xiaohua Chen,et al.  Structure and properties of polypropylene‐wrapped carbon nanotubes composite , 2009 .

[19]  Abbas Ahmadi,et al.  Fractal dimension of soil aggregates as an index of soil erodibility , 2011 .

[20]  Yang Peiling,et al.  Multifractal analysis of soil structure under long‐term wastewater irrigation based on digital image technology , 2007 .

[21]  Yi Li,et al.  Single and Joint Multifractal Analysis of Soil Particle Size Distributions , 2011 .

[22]  Yong-hui Yang,et al.  A Fractal Method of Estimating Soil Structure Changes Under Different Vegetations on Ziwuling Mountains of the Loess Plateau, China , 2006 .

[23]  M. A. Gharaibeh,et al.  Impact of Field Application of Treated Wastewater on Hydraulic Properties of Vertisols , 2007 .

[24]  Weiping Chen,et al.  An overview of reclaimed water reuse in China. , 2011, Journal of environmental sciences.

[25]  P. Minhas,et al.  Hydraulic conductivity and clay dispersion as affected by application sequence of saline and simulated rain water , 1986, Irrigation Science.

[26]  C. P. Murphy.  Thin Section Preparation of Soils and Sediments , 1986 .

[27]  J. D. Rhoades,et al.  Effects of Clay Type and Content, Exchangeable Sodium Percentage, and Electrolyte Concentration on Clay Dispersion and Soil Hydraulic Conductivity , 1978 .

[28]  M. Lado,et al.  Effects of irrigation with different effluents on saturated hydraulic conductivity of arid and semiarid soils. , 2010 .