A method for mapping the spatial variability of soil physical quality

摘要

The objective of this work was to propose a method for mapping the spatial variability of soil physical quality. Basically, the method consisted of mapping the spatial variability of Easily Available Water (E.A.W.), Air Filled Porosity (P.A.) and soilPenetration Resistance (R.P.), using geostatistics, and a standard vector classifier, to scale the physical attributes and classify the Soil Physical Quality (S.P.Q.). The studied site was an area of 6.24 ha pertaining to an Integrated Agroecological Production System (LAPS), located at Seropedica, Rio de Janeiro/BR. A regular georreferenced grid was used to assess and determine the physical attributes E.A.W., P.A. and R.P., respectively, at 0.10, 0.20 and 0.30 m soil depth. The classes of S.P.Q. usedwere: Restrictive (E.A.W.<3.9 mm, and/or P.A.<10%, and/or R.P >2mPa), Suitable (E.A.W. = 3.9-5.5 mm, and P.A. = 10-20%, and R.P.=l-2 MPa) and Optimum (E.A.W. > 5.5 mm, and P.A.>30%, and R.P.< IMPa). All physical attributes presented spatial dependence with fitted spherical (E.A.W. and P.A.) or exponential (R.P.) semivariograms models. Most part of the area was classified as restrictive, at all depth for the sake of low E.A.W., followed by suitable and Optimum, respectively. The method must be tested indifferent environmental conditions.