Effects of Biochar and Synthetic Polymer on the Hydro-Physical Properties of Sandy Soils: Fid-Bau Portal

Effects of Biochar and Synthetic Polymer on the Hydro-Physical Properties of Sandy Soils

Arafat Alkhasha / Abdulrasoul Al-Omran / Anwar Aly

Synthetic polymers, such as polyacrylamide (PAM), and biochar are generally used as soil amendments to improve soil properties. This paper explores a laboratory column experiment conducted to investigate the effects of biochar (pyrolysis at 400⁻450 °C) and polymers, with different application rates, on the hydro-physical properties of sandy soil. The experiment evaluated four rates each of biochar (0.0% (C), 2% (B₁), 4% (B₂), 6% (B₃) and 8% (B₄)) and polymers (0.0% (C), 0.2% (P₁), 0.4% (P₂), 0.6% (P₃), and 0.8%(P₄)), as well as a mixture of them. The infiltration rate decreased significantly when a mixture of biochar and polymers was adopted. B₁ showed a decrease of 32.73% while a mixture of 8% (B₄) and (0.8%) P₄ exhibited a decrease of 57.31%. The polymers increased the infiltration rate at low concentrations (P₁ and P₂) and reduced it at high concentrations (P₃ and P₄). The cumulative evaporation decreased significantly for most treatments. B₁ recorded the highest decrease in cumulative evaporation with a percentage decrease of 31.9%. The highest decrease in hydraulic conductivity (Ks) was for B₁. However, the mixture of B₄ and P₄ resulted in the highest increase in soil moisture content at field capacity compared to the control and other treatments. P₄ and the mixture of B₂ and P₂ showed significant (p < 0.05) increases in the percentage of stable aggregate (SA) in fraction size (0.25⁻0.125 mm). Although the mixture of B₄ and P₄ had the highest increase in soil moisture content, this study recommends using the B₁ treatment on sandy soil in arid environments due to its strong hydro-physical properties and affordability.