Abstract

CASTIGLIONI, Mario Guillermo. Variability analysis of surface soil water content at different spatial scales. Cienc. suelo [online]. 2019, vol.37, n.1, pp.26-37. ISSN 1850-2067.

Several physical, chemical and biological processes that occur in the soil are affected by soil water content. This property is variable both in time and space, with different factors regulating its heterogeneity. The aim of this work was to study the variability, degree and range of spatial structure presented by soil moisture, at different spatial scales and at two depths, in agricultural soils within a basin in the south of Santa Fe, analyzing also the effect of different soil properties on this behavior. Results of soil water content obtained at two depths (0-5 and 5-10 cm) at the plot, landscape unit and basin scale were analyzed in agricultural soils of the Arroyo Ludueña basin (Santa Fe province). Classic statistics and geostatistical analysis was done. It was studied the effect of different soil properties (bulk density, organic matter and different size pores) on the variability and spatial structure of the analyzed variable. Within the range of the average soil water content determined in the different sites (25% to 37%), it was found that the coefficient of variation increased with the sampling scale (plot: 6,2%; landscape unit: 11,5%; basin: 18,1%). In some sites, the correlation coefficients between bulk density, organic matter and some size pores with the gravimetric water content were significant, with values that ranged between 0.24 and 0.68. At the basin scale, a better degree (32%) and a greater range (23000-29000 m) of spatial correlation were found in the studied property, with respect to the landscape unit (75% and 3300 m, respectively) and to the plots (73-83% and 15-25 m, respectively), without finding significant effects of the mean moisture value, the other soil properties and the sampling depth on this behavior.

Keywords : Spatial structure; soil properties; agricultural soils.