How Soil pH Influences Grapes

Hans Walter-PetersonWhen we talk about the influence of the environment on grapes, what we usually mean are things like air temperature, humidity, and sunlight — the things that influence the parts of the vine that are above ground. But the environment where the roots are located — the soil — can be just as crucial to successfully growing grapes. And one of the most important aspects of the soil environment is pH — the measure of how acidic or alkaline the soil is.

Nutrient problems in grapevines are often a result of soil pH, because the nutrients are bound up in the soil or are in a form that the roots are unable to take up. For example, in acidic soils (pH less than 5.5) high amounts of free aluminum and iron precipitate phosphorus (P) out of the soil solution, making P unavailable to the plant. High amounts of aluminum can also impact root growth by inhibiting cell division at the root tip. In alkaline soils (pH greater than 8.0), micronutrients like zinc, iron, and copper become less available to the vines, and it is not uncommon to see deficiency symptoms in these cases.

Proper Timing
The best time to influence the pH of a vineyard is before a single vine goes into the ground. The first option is to find a vineyard site with a native soil pH in the desirable range to begin with, and which needs no adjustment at all. The second option is to adjust the soil pH to a desirable level before the vineyard is planted. In most cases in the Eastern U.S., this will mean needing to raise the pH by adding lime. Unlike some nutrients, limestone does not move through the soil profile very quickly, and therefore the best option to change the soil pH down near the root zone is to apply the amendments to the surface and then use a plow to get the lime down deeper into the profile. Relying on the lime to move through the top 12 to 14 inches of soil and into the root zone on its own would take many years.

Even if the vineyard has a proper soil pH at the time of planting, it will be necessary to occasionally conduct soil tests to determine if it has changed over time. Soils will gradually acidify over time due to the removal of cations like calcium, potassium, or magnesium either by leaching or uptake by plants, acid rain, or the reaction of certain nitrogen fertilizers in the soil (e.g., urea and ammonium nitrate). We generally recommend that soil samples be collected every four to five years in a particular location, unless the grower is in the process of changing pH or nutrient levels. Soil pH is a routine measure that should be included in any basic soil analysis. These soil analyses generally cost around $15 to $20 per sample.

If test results indicate that an adjustment to the pH is necessary, most labs will make a recommendation for how much lime to add to the soil to achieve a certain pH (if that desired pH level is not clear, ask the lab what it is). This recommendation is based on the difference between the actual and desired pH level and the buffering capacity of the soil. The targeted pH level will depend on what varieties are being grown. Labrusca-based varieties are better adapted to more acidic soils, while hybrids and vinifera tend to perform better in more neutral pH soils. Soils with higher clay content or higher levels of organic matter will require more lime to change the pH than sandy or low organic matter soils.

Growers may need to adjust the rate recommended from their samples, depending on the material that they choose to use. Any liming material that is purchased should state the “effective neutralizing value” (ENV) that is used to determine the actual amount of that material to apply. The calculation is straightforward:
Actual lime required x Recommended rate (tons per acre) / ENV (as an integer) x 100

Having the soil pH in a range that is appropriate for the varieties being grown will go a long way to making the environment below ground hospitable for the roots, and can help to minimize the need for supplemental fertilizers. The best time to ensure a proper pH is before planting, by choosing a good site and making any necessary adjustments when it is easiest to do so. But regular soil testing will help to ensure that the soil pH remains in the proper range over the life of the vineyard.

Targeting Soil pH
Soil pH levels will range depending on the type of grape variety. Even if the vineyard has a proper soil pH at the time of planting, it will be necessary to occasionally conduct soil tests to determine if it has changed over time.

Type of grape variety and target soil pH:

  • Natives: 5.5-6.0 pH
  • Hybrids: 6.0-6.5 pH
  • Vinifera: 6.5-7.0 pH
Topics: ,

Fruits Stories

CitrusIndustry Organizations Sound Off On President’s Immigration Plan
November 21, 2014
Agriculture is not given the attention it so sorely deserves when it comes to the immigration debate. Read More
CitrusRamped-Up Predatory Mite Production To Benefit Growers
November 21, 2014
Biologics company Beneficial Insectary now rearing two species in its California facility. Read More
Apples & PearsOn The Road With The International Fruit Tree Association Study Tour To Italy Part 2 [Slideshow]
November 21, 2014
Attention to detail is evident in the production of high quality feathered apple trees at GRIBA’s nursery. Read More
Fruits2014 California Winegrape Harvest: Outstanding
November 21, 2014
It’s the earliest crop of the decade, but still a third in a string of great vintages. Read More
FruitsFetzer Vineyards Pioneers Zero Waste
November 21, 2014
Company achieves top sustainability certification by diverting 98% of its waste from the landfill. Read More
GrapesPerfect Storm Hurts New York Concord Grape Growers
November 21, 2014
More than 10,000 tons of juice grapes are abandoned because of too much production and no market. Read More
FruitsClassic Turkey Day Dinner Costing Consumers More This Year
November 20, 2014
Despite increase, a family of 10 can still get stuffed for less than $50. Read More

The Latest

CitrusReasons Aplenty Florida Growers Should Feel Good Going …
November 24, 2014
Thanks to recent industry achievements, the next 12-month period is shaping up to be a year to remember --- fondly. Read More
FruitsRegistration Opens Dec. 1 For NAFDMA 30th Annual Conven…
November 24, 2014
The five-day event includes bus tours, educational sessions, workshops, and a business exchange in Tennessee in February. Read More
CitrusIndustry Organizations Sound Off On President’s Immig…
November 21, 2014
Agriculture is not given the attention it so sorely deserves when it comes to the immigration debate. Read More
CitrusRamped-Up Predatory Mite Production To Benefit Growers
November 21, 2014
Biologics company Beneficial Insectary now rearing two species in its California facility. Read More
Fruits2014 California Winegrape Harvest: Outstanding
November 21, 2014
It’s the earliest crop of the decade, but still a third in a string of great vintages. Read More
FruitsFetzer Vineyards Pioneers Zero Waste
November 21, 2014
Company achieves top sustainability certification by diverting 98% of its waste from the landfill. Read More
FruitsClassic Turkey Day Dinner Costing Consumers More This Y…
November 20, 2014
Despite increase, a family of 10 can still get stuffed for less than $50. Read More
EquipmentHighlights From EIMA International In Italy [Slideshow]
November 19, 2014
The 2014 edition of the International Agricultural and Gardening Machinery Exhibition (EIMA) boasted a record number of attendees from 124 countries. Read More
FruitsFixing Farm Labor Woes Worth The Extra Effort [Opinion]
November 19, 2014
40th annual Ag Labor Relations Forum encourages outreach and action. Read More
CitrusWomen’s Impact On Agriculture Impressive [Opinion…
November 18, 2014
Florida Agriculture Commissioner Adam Putnam says the long-term sustainability of farming depends on our youth. Read More
Business PlanningFarm Executive Workshop To Build Management, Leadership…
November 17, 2014
Penn State Extension offering unique learning event for those looking to bolster business. Read More
Farm ManagementGrowing Produce Without Risk Management Program Is A Ba…
November 14, 2014
Utilize available insurance tools to ensure opportunities for long-term survival and success. Read More
FruitsWestern Growers Frustrated By Shutdown Of Ports
November 14, 2014
Pacific Maritime Association is accusing union of intentional work slowdown. Read More
Farm ManagementSouth Florida Farmers Going Extra Mile For Everglades C…
November 12, 2014
Growers in one of the most unique and regulated areas in the world have exceeded benchmarks in the quest to restore the ‘River of Grass.’ Read More
FruitsOur Roots Run Deep In The Pacific Northwest [Opinion]
November 11, 2014
A lot is changing in the Pacific Northwest fruit industry. Many of the most important things are not. Read More
FruitsRosBREED2: Disease Resistance Plus Horticultural Qualit…
November 11, 2014
This new project will develop and apply modern DNA-based tools to deliver new cultivars with superior product quality and disease resistance. Read More
FruitsWin Jan Cook Mack’s “Stand By Me Reds”…
November 11, 2014
The original “Stand By Me Reds” painting will be given away to one lucky attendee at this year’s Washington State Horticultural Association meeting. Read More
FruitsProduce People, It’s Time To Pony Up [Opinion]
November 10, 2014
Fruit grower associations need to think long and hard about how they can better serve our country’s youth by marketing their products more aggressively. Read More