1. Coastal soils: Issues with salinity
Mark Battany, Viticulture/Soils Farm Advisor
San Luis Obispo & Santa Barbara Counties

2. Quick review of salinity
Water + salts
Pure water
Irrigation
Evapotranspiration
Salts in root zone
Vineyard soil
Leaching
Salts below (or away from) root zone

3. Three salinity situations
Restricted drainage
Salts can accumulate to high levels
No leaching of rootzone
Free drainage conditions, occasional leaching
Salts can increase, but to some limit
Will still affect vineyard performance

4. Restricted drainage
East of Mendoza, Argentina

5. Limited natural rainfall leaching
Elqui Valley, Chile; source:
Valle del Elqui, Chile

6. Occasional leaching

7. Effects on soil chemistry
Electrical conductivity (ECe)
Plant growth decreases as soil EC increases
Sodium
Degrades soil structure, toxicity at high levels
Chloride, boron
Toxicity at high levels
Bicarbonate
Increases soil physical degradation pH
Nutrient availability

8. Salt source: groundwater
Data from 56 wells in the Paso Robles area
Source: Paso Robles Groundwater Basin Study
Increasing problem potential
Major problem potential

9. Vine productivity vs. soil EC
100%
Relative growth or yield 0%
Soil EC (dS/m)

10. Specific toxicity

11. Sodium Sodium salts; disperse organic matter & clay
Calcium salts; from amendments

12. Soil structure degradation
Effects of sodium and bicarbonate
Vine growth, yield
Soil degradation >>>

13. Paso Robles salinity survey
Soil EC
(dS/m)
6.5
5.4
4.2
3.0
1.8
2006 data
0.6

14. salinity surveys

15. Soil EC values (2007)

16. Deeper soil salt fate
Samples taken in May 2010, after relatively wet winter

17. Irrigation water analysis
meq/L
mg/L pH
ECw
SAR Ca Mg Na Cl
HCO3 B
7.8
1.81
4.6
3.4
6.0
9.9
6.4
4.8
0.93
Each season of irrigation water (1.25 ft) applies about 775 lbs of sodium per acre, and about 3.1 lbs of boron per acre
Bicarbonate hazard low: Ca + Mg > HCO3

18. Sample site: Clay content
Percent clay
Sample site: Clay content

19. Soil pH
Sample site: pH

20. Electrical
conductivity
Sample site: ECe

21. Sodium
Sample site: Sodium

22. Chloride
Sample site: Cl

23. Boron
Sample site: Boron

24. Managing vineyard salinity
Measure soils and water; heed recommendations
Correct any drainage problems
Adjust water chemistry
Apply gypsum (or acid) as needed
Leach with irrigation when rainfall insufficient
Use tolerant rootstocks, varieties

25. Field salinity measurement

26. Drainage

27. Adjust water chemistry
Acidification
Acid injection
Sulfur burner
Critical to manage waters with high pH and bicarbonates
Blending with better water if available
Reverse osmosis not feasible economically
Miracle devices...magnets, electrodes, etc.

28. Gypsum Helps displace sodium Counteracts bicarbonate
Can use acid instead if soil has “free lime”
Still need leaching water to remove sodium
Gypsum will raise soil EC slightly

29. Additional leaching

30. Use more tolerant rootstocks
100%
1103P, 140R
Salt Creek
Relative growth or yield 0%
Soil EC (dS/m)

31. Use more tolerant varieties
Example: Syrah vines in a block of Cabernet Sauvignon

32. Summary
Central Coast salinity conditions are manageable (for the most part) but will require attention to keep impacts from becoming economically damaging
Thanks:
American Vineyard Foundation
ASEV
Grower support on Central Coast

33. Retrofitting with sprinklers

34. Salt toxicities