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
Apples & PearsMeet USApple’s Class of 2015 Young Apple Leaders
March 27, 2015
Young decision-makers see trip as an opportunity make sure the voice of the apple industry is heard by representatives. Read More
GrapesGlassy-Winged Sharpshooter Found In Marin County
March 26, 2015
This pest, known to spread Pierce’s Disease, could devastate California winegrapes. Read More
GrapesFirst Raisin Grape That Dries Naturally On Vine Developed
March 26, 2015
The new Sunpreme variety eliminates the need for growers to cut into woody canes before harvest. Read More
Fresh From Florida Strawberry Parfait recipe
BerriesNew Partnership Sends Florida Strawberries To Puerto Rico
March 26, 2015
Latest addition extends Sunshine State’s agricultural export reach in the Caribbean. Read More
drought management; irrigation; water management
FruitsHow To Become A Soil Sleuth
March 26, 2015
To correctly apply the proper nutrients at the right rates, you need to know where your fields are deficient and how to correctly diagnose a disorder. Read More
Cold ProtectionWind Machine, Electric Pruners Donated To MSU Research Center
March 25, 2015
New equipment to help protect research blocks from frost damage and provide center with latest technology. Read More
CitrusProposed Farm Bill Provision To Limit Payments To Non-Farmers
March 25, 2015
USDA has proposed a new rule which would limit payment to those who are only actively engaged in farming. Read More
The Latest
FruitsSounding Off On GMOs: The Arctic Apple Decision
March 27, 2015
Industry leaders share their feelings on the recently approved genetically modified apples. Read More
FruitsAhead Of The Curve, Part 2
March 27, 2015
Get educated with great resources in the tree fruit industry available at your fingertips. Read More
drought management; irrigation; water management
FruitsHow To Become A Soil Sleuth
March 26, 2015
To correctly apply the proper nutrients at the right rates, you need to know where your fields are deficient and how to correctly diagnose a disorder. Read More
Cold ProtectionWind Machine, Electric Pruners Donated To MSU Research …
March 25, 2015
New equipment to help protect research blocks from frost damage and provide center with latest technology. Read More
CitrusProposed Farm Bill Provision To Limit Payments To Non-F…
March 25, 2015
USDA has proposed a new rule which would limit payment to those who are only actively engaged in farming. Read More
FruitsHow To Get Started With Partnerships And Sponsorships
March 25, 2015
Mark Saunders of Saunders Farm says your business is never too small or too big to get more value for what you do on your farm. Read More
FruitsValue Through Partnerships And Sponsorships [Opinion]
March 25, 2015
Mark Saunders of Saunders Farms says admission is one way to get value for what you do, but sponsorships and partnerships are the next level. Read More
FruitsWorld Ag Expo 2015: New Tools For Fruit Growers
March 24, 2015
From wind machines to solar-powered pumps, here is some of the new equipment on display this year's edition of the nation's largest farm show. Read More
FruitsRare Leafhopper Found In Shipment At Delaware Port
March 24, 2015
This is the second time this pest has been discovered by U.S. Customs and Border Protection agriculture specialists. Read More
FruitsNew Pome, Citrus Thinning Tool Approved
March 24, 2015
Refine plant growth regulator receives federal registration. Read More
CitrusFarm Bureau Says WOTUS Rule Would Ignore Exemptions
March 24, 2015
Common farming practices may be vulnerable to Clean Water Act enforcement under the rule. Read More
FruitsUC-Davis Seed Biotech Center Receives Funds For Continu…
March 24, 2015
The university received $500,000 in funds toward a $2.5 million goal from seed company Limagrain. Read More
FruitsTips For Pear Psylla Management
March 24, 2015
Dormant oil applications should start as growers begin to experience warmer, mild weather. Read More
FruitsBiocontrols Event Draws Rave Reviews
March 23, 2015
Conference devoted to discussion of biological means to control pests and diseases held last month in Fresno, CA. Read More
brown marmorated stink bug dog search team
FruitsUSDA Uses Man’s Best Friend To Track Stink Bug
March 23, 2015
It's all paws on deck to find brown marmorated stink bug's overwintering sites. Read More
CitrusCalifornia Unveils $1 Billion Drought Package
March 23, 2015
Governor, legislative leaders, announce $1 billion emergency drought legislation. Read More
CitrusFeed A Bee Campaign Aims To Plant 50 Million Flowers
March 23, 2015
Bayer CropScience announces program to increase forage opportunities for critical pollinators. Read More
Florida organic strawberry research
FruitsParry America Aims To Boost Biopesticide Business Via S…
March 19, 2015
Brian Dockery tapped to drive growth of company’s specialty crop sector. Read More