Abstract

SILVA, Júlio J. N. et al. Spatial variability of growth parameters of castor bean crop and of physico-chemical attributes in Fluvisol. Rev. bras. eng. agríc. ambient. [online]. 2010, vol.14, n.9, pp. 921-931. ISSN 1807-1929.  http://dx.doi.org/10.1590/S1415-43662010000900003.

The aim of this study was to evaluate the potential of the castor bean crop in a Fluvisol of Pernambuco "Agreste". The research was conducted at the Nossa Senhora do Rosário Farm, Pesqueira-PE. The BRS 188 - Paraguaçu castor bean was cultivated, which, according to the literature, is suitable for the local conditions. The experiment was conducted under rainfed condition. Classical statistics and geostatistics techniques were applied to observe the degree of dependency for the attributes and the spatial variability of soil texture, electrical conductivity of saturation extract (CEes) and sodium (Na) content, as well as the crop stem diameter and height of the plants. All parameters adjusted to a Normal distribution, except stem diameter, at 200 days after sowing, showing a medium to low degree of spatial dependence. Among the studied variables only CEes showed pure nugget effect, adjusting the others to theoretical models of semivariograms. The produced contour maps allowed the observation of more heterogeneous areas, mainly in the most sandy area where better crop growth was verified and where a local management strategy must be developed.

Keywords : alluvial valley; geostatistics; Ricinus communis.