Effect of Polysaccharides, Clay Dispersion, and Impact Energy on Water Infiltration

Abstract

AbstractEffects of clay dispersion, impact energy of water drops, and chemical amendments on crust formation and infiltration rate (IR) of Haplic Durixeralf soil were studied using a sprinkler infiltrometer. The soil was subjected to two impact energies, high energy = 240 J m−2 h−1 and low energy = 0, and to three waters: (i) distilled water [DW, electrical conductivity (EC) < 0.05 dS m−1], (ii) saline water (SW, EC = 5.0 dS m−1), and (iii) regular water (RW, EC = 1.0 dS m−1). The chemical amendments, polysaccharides, guar derivatives were supplied with the DW and RW and with high impact energy. Crust formation by the impact energy was found as a dominant factor in the IR reduction. This factor reduced the total soil infiltration capacity by more than 40%. Conversely, clay dispersion in the soil surface reduced the total soil infiltration capacity by 24%. Likewise, it was found that clay dispersion in the soil surface decreased the hydraulic conductivity of the crust and sharply increased its hydraulic resistance. The polymers had an amendatory effect on the IR. The polymers apparently adsorbed on the particle surfaces and acted as a cementing material holding primary particles together against the destructive forces of the water drops. The order of the maximum effect of the chemical amendments (0.01 kg m−3), that were supplied in DW, on the maintenance of IR was: high charge cationic polymer (HCCP) > low charge cationic polymer (LCCP) ≫ nonionic polymer > anionic polymer (had no effect). A concentration of 0.01 kg m−3 of HCCP and LCCP in RW prevented crust formation and preserved the high initial IR of the soil throughout the water application period. The HCCP and LCCP under sprinkled DW and RW conditions apparently adsorbed at the soil surface and did not move with the water into the soil layer.