| Abstract: | In this study, the effectiveness of artificial zeolite and hydrated lime, as amendments, to reduce surface runoff and soil loss from acidic soil taken from Yamaguchi prefecture in Japan was assessed. Air‐dried soil aggregates (?2 mm) were amended with zeolite at 10% and with lime at 0.5%. The amended aggregates were packed to an average dry‐bulk density of 1.30 Mg m?3 in small soil trays and subjected to simulated rain intensities of 30 and 60 mm h?1. Two pretreatments were used before subjecting them to simulated rainfall: (a) soil incubated for 2 weeks and (b) soil kept for 5 months, irrigated every two days. The data indicated that surface runoff was characterized by three phases. The amendments' impact was most significant during the first two phases as the amendments induced the formation of particles sized ? 106 µm, which are mostly responsible for the crusting. Amendments decreased soil losses, and the magnitude of reduction became higher when the irrigation pretreatment was applied before simulated rainfall. The amendment led to increase in soil organic carbon, wet aggregate stability, saturated hydraulic conductivity, and the large particle size in the sediment. The results suggest that surface runoff and soil loss in acidic soils can be substantially reduced by application of zeolite or lime, and this is attributed to the increase in wet aggregate stability and the large particle size in the sediment because of the amendments, and in this regard zeolite is more effective than lime. |
