THE INFLUENCE OF THE SOIL CONDITIONER AGRI-SC ON SPLASH DETACHMENT AND AGGREGATE STABILITY

The influence of the soil conditioner 'Agri-SC' on splash detachment a nd water-stable aggregation of an erodible clay Vertisol from Oahu, HI , was assessed. Laboratory rainfall simulation was used to assess spla sh detachment from soil treated with 0 (untreated control), 0.3, 3.0, 30, and 300 l ha(-1) of Agri-SC. Results indicated that the quantity o f sediment splashed was significantly lower for Agri-SC application ra tes of 0.3 and 3.0 l ha(-1) (rates are equivalent to 1 and 10 times th e manufacturer's recommended rates, respectively), than for the contro l, or for Agri-SC applied at 30 and 300 1 ha(-1) (100 and 1000 X, resp ectively). A second experiment was designed to test the influence of A gri-SC on water-stable aggregation of the Vertisol. Aggregates were su bjected to rapid immersion in solution, shaken and washed through a se ries of sieves. Data indicated that there were no statistically signif icant differences in geometric mean aggregate diameter between the unt reated and treated aggregates. The effect of the active ingredient, am monium laureth sulfate (an anionic surface active agent) on splash and erodibility are discussed. These preliminary results indicate that fu rther testing of Agri-SC is warranted on a variety of soils with diffe rent textures and mineralogies. (C) 1998 Elsevier Science B.V. All rig hts reserved.