Benefits of Treated Rice Straw on Soil Hydraulic Properties under Saline-Sodic Irrigation Water

Document Type : Original Article

Authors

Soils Dept., Fac. Agric., Mansoura Univ., Mansoura, Egypt

Abstract

Egypt is an arid country whose agricultural production depends entirely on ‎irrigation, and it suffers from a severe shortage of fresh water resources. Reuse of ‎agricultural wastewater is therefore inevitable, especially in the central and ‎northern regions of the Egyptian Nile Delta. Recently, the addition of biochar is considered one of a climate-smart farming practice in sustainable agriculture. Therefore, a columns experiment was conducted at the laboratory of Soils Dept., Fac., Agric., Mansoura Unvi. to assess the role ‎of treated rice straw on alleviating the adverse effects of irrigation by agricultural ‎drainage water (low-quality water) on soil physical and hydraulic properties (water movement). The treatments of the experiment include two types of soil texture: (S1) Clay loamy soil and (S2) Loamy soil, two types of irrigation water: (I1) Tap water and (I2) Agricultural drainage water (severe salty and sodic) and two types of treated rice straw: (C1) Rice straw compost (RSC) and (C2) Rice straw compost biochar (RSCB), beside (C0) Control. Results showed that applying both RSC and RSCB increased soil's resistance against negative effect of low-quality water, not only that, but it improves the soil physical and hydraulic properties.‎ The addition of treated rice straw in ‎particular RSCB caused ‎an increase of the ‎soil hydraulic properties i.e. saturated hydraulic conductivity (‎Ks), unsaturated hydraulic conductivity K(θV), specific fluid flux (q) and intrinsic ‎permeability (k) as a result of the positive change in soil bulk density (ρb), mean pore diameter (d) ‎and porosity (E).‎ Based on these results, the two types of treated rice straw, especially RSCB could improve soil resistance against degradation caused by low-quality water irrigation through improving aggregation process, soil structure and water movement across soil matrix.

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