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Effects of the spatial variability of soil hydraulic properties on water dynamics in cranberry production Gumiere, S.J. ; Caron, J.; Périard, Y.; Lafond, J. NACREW-2013 - Québec Dép. Sols et Génie Agroalimentaire, FSAA, U. Laval. silvio-jose.gumiere@fsaa.ulaval.ca. Introduction.
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Effects of the spatial variability of soil hydraulic properties on water dynamics in cranberry productionGumiere, S.J.; Caron, J.; Périard, Y.; Lafond, J.NACREW-2013 - QuébecDép. Sols et Génie Agroalimentaire, FSAA, U. Laval.silvio-jose.gumiere@fsaa.ulaval.ca
Introduction • Soil hydraulic properties may present spatial variability and dependence at the scale of watersheds or fields even in man-made structures, such as cranberry fields. • Water management in cranberry fields should take into account the spatial variability of soil properties. • First we need to characterize the spatial variability ant its sources.
What are the sources of variability in the field? We need to characterize these sources in order to understand their effects on crop productivity.
Material and Methods: Site A Field observations: • Irrigation system; • Sat. hydraulic cond. (Ksat); • Soil water retention curves; • Matric potential; • Photosynthesis; • Ground water level; • Crop productivity. Site B
Material and Methods: Geostatistics and interpolation • Variographic analyses • Kriging • Thin plate splines (TPS) • Entropy methods …
Material and Methods: • Variographic analyses • Kriging • Thin plate splines (TPS) • Entropy methods Find homogeneous zones
Results : Characterization and interpolation • Saturated hydraulic conductivity; • Spatio-temporal variability of soil matric potential; • Crop productivity;
Saturated hydraulic conductivity of two depths (20 and 40cm) Very slow zones Slow zones Fast zones Site A Site B
Site A Soil Tension at 10 cm (root zone) Site A kPa Before irrigation After irrigation T1 + 1 h
Soil Tension at 10 cm (root zone) Site B kPa Before irrigation After irrigation T1 + 1 h
Site A, productivity Site B, productivity 1000 x lbs/acre 1000 x lbs/acre
Conclusion • Spatial patterns of Ksat at both sites. • Matric potential seems to follow the same patterns. • Crop productivity has high spatial variability. • Site A, low productivity in fast zones; • Site B, low productivity in very slow zones;