1. 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 silvio-jose.gumiere@fsaa.ulaval.ca

2. 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. Introduction

3. What are the sources of variability in the field? Variability in crop productivity Variability from soil properties Variability from root water uptake Variability from irrigation system Variability from ground water We need to characterize these sources in order to understand their effects on crop productivity.

4. Material and Methods: Field observations: Irrigation system; Sat. hydraulic cond. (Ksat); Soil water retention curves; Matric potential; Photosynthesis; Ground water level; Crop productivity. Site A Site B

5. Material and Methods: Geostatistics and interpolation Variographic analyses Kriging Thin plate splines (TPS) Entropy methods …

6. Material and Methods: Variographic analyses Kriging Thin plate splines (TPS) Entropy methods Find homogeneous zones

7. Results : Characterization and interpolation Saturated hydraulic conductivity; Spatio-temporal variability of soil matric potential; Crop productivity;

8. Saturated hydraulic conductivity of two depths (20 and 40cm) Site ASite B Slow zones Fast zones Very slow zones

9. Soil Tension at 10 cm (root zone) kPa Site A Before irrigation After irrigation T1 + 1 h Site A

10. Soil Tension at 10 cm (root zone) kPa Before irrigation After irrigation T1 + 1 h Site B

11. Site A, productivitySite B, productivity 1000 x lbs/acre

12. 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;

13. Thank you! Questions???