Horizontal Infiltration of Water in Soil Columns as Affected by a Gel -Forming Conditioner.

We conducted a laboratory experiment on the interrelationships among five rates, R(0 to 1.6% ), of a gel-forming conditioner (Jalma-containing 24.5% humic acids and 3.8% polysaccharides), water penetrability (  ), weighted-mean diffusivity (D), swelling index (S), and effective mean pore radius (r) of a loamy sand, a sandy loam, and a loam. For each of the three soils, the results indicated a highly significant linear increase in S and a consequency exponential decrease in r,  , and D with increase of R. The effects of Jalma on these parameters were more marked on the loamy sand than on the other two soil samples. Addition of 0.2, 0.4, 0.8, and 1.6% Jalma to the loamy sand sample significantly reduced by about 19, 55, 83, and 98%, respectively, and D by about 38, 76, 96, and 100%, respectively. The highest rate almost compelety sealed the soil independent of its texture and reduced D to almost zero. We concluded that 0.4% Jalma is the optimum rate for soil water conservation. We argue that Jalma addition causes swelling of the soil matrix, reduces the effective mean pore radius, and consequently reduces and D. The effective mean pore radius proved to be a reliable predictor of D and  of the soil samples studied independent of their texture:  = 2.548r (r = 0.960), and D = 3.303r (r = 0.958)