Abstract
Sandy soil was uniformly treated with a cross-linked sodium polyacrylate gel-conditioner, Acryhope, to study the changes in soil physical properties and their effect on water movement under ponded and sprinkler infiltrations and reduction in evaporation loss. The conditioner was applied to the soil as dry grains ranging from 0.2 to 1 mm in size and at five concentrations (C) ranging from 0 to 1% (d.wt.). Laboratory measurements showed an exponential decrease in saturated hydraulic conductivity and an increase of available water capacity with an increase of C. Relative expansion (L
r
) at saturation increased from 0 to 0.5 with an increase of C from 0 to 1%. Water diffusivity (D
θ
) substantially decreased with an increase of C. At a water content (θ) equal to 30% (Vol.), D
θ
was reduced by 54% for C = 0.25%, 90% for C = 0.50%, and 100% for C = 1%. There were two distinct stages of water movement under ponded infiltration. The first stage, where most of the expansion occurred, was characterized by increased wetting front (L) and cumulative infiltration (D) with an increase of C. The second stage exhibited a reverse effect, i.e., L and D decreased with an increas of C. Under a sprinkler infiltration, D was not affected by C, but L was decreased by increasing C. Although the values of the absolute expansion under ponding were higher than those under sprinkling with the corresponding C, the L
r
values were higher under sprinkling due to the reduced advance rate of wetting front. Water content (θ) increased in the first 20 cm depth by increasing C under vertical infiltration. The evaporation rate was reduced in the presence of Acryhope.