Revista Brasileira de Engenharia Agrícola e Ambiental
Print version ISSN 1415-4366
SANTOS, Karla S. et al. Spatial variability of physical attributes of soil in alluvial valley of semiarid region of Pernambuco state. Rev. bras. eng. agríc. ambient. [online]. 2012, vol.16, n.8, pp. 828-835. ISSN 1415-4366. http://dx.doi.org/10.1590/S1415-43662012000800003.
Soil physical and hydraulic characteristics are relevant for agricultural management, particularly at irrigation districts. The objective of this study was to evaluate the spatial variability of physical attributes of soil in an alluvial valley in the semiarid region of Pernambuco State, at the Ipanema River Watershed. Statistical techniques and geostatistics were applied to observe the degree of dependence and the spatial variability of soil physical properties, in plots adopted for communal agriculture. The coefficient of variation for the hydraulic conductivity was high, medium for soil resistance to root penetration and for sand, clay and silt. For bulk density, particle density and porosity, however, such coefficient was low. Spatial dependence structures were investigated, with ranges spanning from 135 m, for soil hydraulic conductivity, to 465 m, for silt content. Contour map was produced by kriging interpolation, representing the spatial variability of hydraulic conductivity, which showed moderate spatial dependence. Resistance to root penetration, soil density and particle distribution presented spatial random behavior, for the adopted spatial scale. It was possible to identify regions with higher agricultural potential. From the produced map, it was highlighted that loam soils usually present higher resistance to root penetration, and low hydraulic conductivity.
Keywords : hydraulic conductivity; penetration resistance; geoestatistics.