Effect of Land Use in Soil Silicophytolith Pool in Pampean Region, Argentina

Abstract

Abstract Aims Silicophytoliths contributes to the pool of amorphous silica that is incorporated into soils acting as an intermediate in the biogeochemical silica cycle. Soils of the Argentine Pampas are used for agro-livestock practices resulting in nutrient loss and soil degradation. In order to estimate how land use modifies different soil properties and how these alter the silicophytolith content of the soil, soil properties of different sites, silicophytolith content of plant species, dung and soils from different sites (pasture, cultivated field and reserve) were studied. Methods We examined soil, dung and plant phytolith contents and soil properties of sites with different soil use (pasture, cultivated field and reserve). Silicophytoliths from plants and dung were extracted by a calcination technique. Soil properties and phytolith content were measured or obtained by routine techniques. Differences between sites were analyzed by non-parametric and multivariate analyses. Results The production of silicophytoliths by crops was higher than another species. No close relationship between silicophytoliths produced by plants and those found in soils. The highest silicophytolith content was observed in the reserve and the lowest concentration in the cultivated field due to the extraction of the plants. Phytoliths had a significant correlation positive with organic matter and negative with pH. Conclusions Agro-livestock management modifies soil properties and the amounts of silicophytoliths in soils. Important changes in the silicophytolith pool are observed in the cultivated field. The results suggest that taphonomic processes in soils should be taken into account in palaeoecological studies.