coastal soils: issues with salinity mark battany, viticulture/soils farm advisor san luis obispo...
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Coastal soils: Issues with salinity
Mark Battany, Viticulture/Soils Farm AdvisorSan Luis Obispo & Santa Barbara Counties
Quick review of salinity
Vineyard soil
Irrigation Evapotranspiration
Pure waterWater + salts
Salts in root zone
Salts below (or away from) root zone
Leaching
Three salinity situations
• Restricted drainage– Salts can accumulate to high levels
• No leaching of rootzone– Salts can accumulate to high levels
• Free drainage conditions, occasional leaching– Salts can increase, but to some limit– Will still affect vineyard performance
Restricted drainage
East of Mendoza, Argentina
Limited natural rainfall leaching
Valle del Elqui, Chile
Occasional leaching
19531956
19591962
19651968
19711974
19771980
19831986
19891992
19951998
20012004
20072010
0
5
10
15
20
25
30
35Paso Robles winter rainfall, 1952/53 - 2010/11
Year
Winter rain-fall,inches
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
Salt source: groundwater
0
1
2
3
4
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55
Well water ECw
(dS/m)
Data from 56 wells in the Paso Robles areaSource: Paso Robles Groundwater Basin Study
Increasing problem potential
Major problem potential
Vine productivity vs. soil EC
Soil EC (dS/m)
0 1 2 3 4 5 6 7 8 9 10
Relative growth oryield
0%
100%
Specific toxicity
Sodium
Sodium salts;disperse organic matter & clay
Calcium salts;from amendments
Soil structure degradation• Effects of sodium
and bicarbonate
Soil degradation >>>
Vine growth,yield
Paso Robles salinity survey
PasoRobles
San Miguel
Shandon
PasoRobles
San Miguel
Shandon
6.5
0.6
3.0
4.2
5.4
1.8
Soil EC(dS/m)
2006 data
2006-2009 salinity surveysAverage soil electrical conductivity (ECe)
2.802.512.23
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
2006 2007 2009
Year
ECe (dS/m)
Soil EC values (2007)
0
20
40
60
80
100
0 2 4 6 8 10
Soil electrical conductivity, ECe (dS/m)
Relative growth
(%)
43% exceeded threshold
Deeper soil salt fate
Samples taken in May 2010,after relatively wet winter
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
Sample site: Clay content
Clay (% )
192022232528313333
30
60
90
120
150
180
210
240
0
Vine row Row m iddle
Soil depth(cm )
Percent clay
Sample site: pH
pH
5.86.06.26.46.66.87.07.27.4
30
60
90
120
150
180
210
240
0
Vine row Row m iddle
Soil depth(cm )
Soil pH
Sample site: ECe
ECe(dS/m )
1.01.52.02.53.03.54.04.55.0
30
60
90
120
150
180
210
240
0
Vine row Row m iddle
Soil depth(cm )
Electrical conductivity
Sample site: Sodium
Na (m eq/L)
469121518212427
30
60
90
120
150
180
210
240
0
Vine row Row m iddle
Soil depth(cm )
Sodium
Sample site: Cl
Cl (m eq/L)
1357911131517
30
60
90
120
150
180
210
240
0
Vine row Row m iddle
Soil depth(cm )
Chloride
Sample site: Boron
B (m g/L)
0.00.10.20.30.40.50.60.7
30
60
90
120
150
180
210
240
0
Vine row R ow m iddle
Soil depth(cm )
Boron
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
Field salinity measurement
Drainage
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.
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
Additional leaching
Use more tolerant rootstocks
Soil EC (dS/m)
0 1 2 3 4 5 6 7 8 9 10
Relative growth oryield
0%
100%1103P, 140RSalt Creek
Use more tolerant varieties
Example: Syrah vines in a block of Cabernet Sauvignon
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
Retrofitting with sprinklers
Salt toxicities