Effect of artificial zeolite on sodic soil resistance to water erosion

Kaneuchi, T.; Yamamoto, T.; Moritani, S.; Inoue, M.; Andry, H.; Saito, H.; Roy, K.

Effect of artificial zeolite on sodic soil resistance to water erosion

2013

Sadie soil (SS) has been known to not only inhibit plant growth but also increase soil erodibility, which is a serious environmental problem for dryland agriculture. Therefore, reclamation of SS is needed for soil conservation in drylands. Artificial SS was prepared to study changes in the soil aggregation characteristics of SS. The effectiveness of artificial zeolite (AZ) in reducing soil erodibility was evaluated under 60 mm /h of simulated rainfall. Aggregates with sizes smaller than 106 micro m in the SS increased by a factor of 3.6 relative to those in the original soil, which can be explained by clay dispersion induced by sodium ions from the SS. Application of 10% AZ into the SS increased the fraction of aggregates larger than 2000 micro m in size, and resulted in an increase of 57 % in the mean weight diameter (MWD), which in turn contributed to an increase in the saturated hydraulic conductivity. In the simulated rainfall experiment, reduction of surface runoff was not observed as a result of the application of AZ to soils. However, soil sediment decreased by 36 % and 47 % relative to the control samples when soils were amended with 5 % and 10 % AZ, respectively. Because the dispersion of aggregates was suppressed by the increased electrolyte concentration in the soil solution, the AZ application decreased soil detachment caused by surface runoff. With respect to the impact of initial soil moisture, larger amounts of sediment runoff were observed in the wetted condition, which might be the result of aggregate dispersion in the initial stages of rainfall.

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