Grape Production in New York Soil pH and Mineral Nutrition of Vitis vinifera Varieties
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In what way do Vitis vinifera varieties different from Native American or Hybrid grape varieties in their nutritional requirements?

There are several important differences between the way that a typical Native American variety (Vitis labrusca) and a typical European variety (V. vinifera) respond to different soils. The home range of V. labrusca is New England, an area dominated by acid soils formed from granitc rocks. Most plants do not thrive in soils below pH 5.6, but V. labrusca based varieties are very tolerant of very acid (<pH 5.6) soils. Conversely they do not toleratef high pH soils. When grown in a soil with a rich supply of calcium (high pH), the roots of most Native American varieties are not able to absorb sufficient Iron to meet the plant's need. Because iron is a component of chlorophyl, the resultant plants lack green color and do not thrive.

North American grape species growing in a high pH soil. The yellow color is because the vine was not able to acquire its iron requirment. Note that other vines in background, which tolerate this high pH soil, have normal, green leaves.

When we established a test planting of V. vinifera varieties in an excellent Concord (V. labrusca) soil, the vinifera did not thrive. Vinifera leaves showed various growth abnormalities and symptoms associated with mineral nutrient imbalances such as magnesioum and phosphorous deficiency symptoms and those of maganese and iron toxicities.

Vitis vinifera vine growing in an acid soil on Long Island New York and displaying the characteristics of "Sauerschaden". The yellow chlorosis is caused by low magnesium and calcium concentration. The red flecking is associated with low phosphorus and the marginal necrosis is has been ascribed to toxic accumulations of iron and/or manganese. Such vines produce fruit with very high fruit pottasium concentration which produce high pH unstable wines.

A literature search revealed that these symptoms had been well described in the Moselle area where the condition was called, Sauerschaden or acid sickness.

Hyrid varieties behave as hybrids would be expected to behave. Some are as sensitive to high or low soil pH as are their parents. Others are intermediate in sensitivity.

The Essential Elements:

To function grapevines need light energy and a proper supply of the following elements.

Macro-Elements		Micro-Elements
From Air & Water	From the Soil	From the Soil
Carbon, Hydrogen, Oxygen	Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Sulfur	Iron, Manganese, Boron, Molybdenum, Copper, Zinc, Chlorine, Cobalt

Carbon, hydrogen and oxygen are supplied from the air and water. The other elements are called mineral or fertilizer elements and must be obtained from the soil

In spite of the difference between grape species in adaptation to different soils, healthy plants of the various species attain very similar concentrations of mineral nutrients in their tissues, and studies have shown that the leaf or petiole mineral element concentration associated with deficiency or toxicity symptoms is also very similar among species.

Optimal mineral element concentrations for fall collected grape petioles
Element	Low	High
Phosphorus	0.1 %	0.3%
Potassium	<1%	>2.5%
Magnesium	0.25%	0.5%
Manganese	100 ppm	1,500 ppm
Copper	5 ppm	15 ppm
Boron	<30 ppm	100 ppm
Zinc	<30 ppm	50 ppm

The values in the above table are meant to be guidelines. The critical concentration of a mineral element is the minimum needed to prevent its characteristic deficiency symptoms (see - grapevine mineral deficiency symptoms) associated with that element. The values given in the above table define a "working range". In monitoring field performance, vine petioles (leaf stems) which fall in the above range of values are considered satisfactory.

Remember the supply of mineral nutrients available in the soil will depend upon several factors

1. The concentration and balance of mineral elements in the soil.
2. The pH (acidity) of the soil.
3. The rooting depth of the soil.
4. The water supply.
5. The method of vineyard floor management (clean cultivation, cover crops, mulching, etc.)
6. The extent of correction of problems through provision of soil drainage, addition of organic
matter organic matter and the addition of fertilizer.

Soil pH

As indicated above, soil pH is a critical factor in New York vineyards. The soil pH is determined by the proportion of acidic (hydrogen and aluminum) and basic (primarily magnesium and calcium) elements in the soil. Most soils in New York date from the last advace of the glaciers. Their composition is a reflection of the rocks that made up the glacial till or the outwash materials that form the sub-soils.

Except fot the Adirondack region, most bedrocks of New York were laid down under deep or shallow seas. Deep seas were cold and sediments accumulated as mud or sand deposits which became shales or sandstones when compressed. Warm seas encouraged the growth of animal and plant life and resulted in reef formation. These became limestones. The Onandoga escarpment is an important feature of New York state (see gold band in figure above). It is the remains of a former reef; among other things it provides the hard capstone over which the Niagara river flows to form Niagara Falls.

The primary vineyard soils of New York had one of three origins.

1. Glacial outwash

The melting glaciers meant higher lake levels and tremendous water flows in rivers. This resulted in stranded beaches and sand bars which form the gravel soils along Lake Erie, various bands of gravel soils along the Finger Lakes and the silt/loams of Long Island.

2. Lake deposits

Finer mineral particals did not settle out along the margin of bodies of water, but were swept into the glacial lakes where they settled as deposits of finely divided material which became silts and clays.

3. Limestone:

Portions of the limestone escarpment were carried south by the glacier and smeared over the northern Finger Lakes. The soils which developed from this parental material have higher pH. In general, the subsoil pH is high at the north end of the Finger Lakes and decreases in pH as one travels south. The acid gravels, sands and shales along Lake Eried and the southern Finger Lakes proved to be well fitted to Native American grapes and the New York industry developed in those regions. An increase in V. vinifera production has encouraged vineyard establishment at the northern ends of the Finger Lakes.

Generalized soil map of New York

click for larger map

These associations can be clearly seen in the general soil map of New York. It indicates soils with limestone as greenish, those from acid shales and sandstones as pink to red. Yellows indicate the glacial outwash soils and blues show the lake depositied soils. These can be compared to the production regions (click here for map).

Aluminum, soil pH and Grapevine Growth

Cations are positively charged ions. Soil pH is a measure of the concentration of hydrogen ions. This figure shows that at low soil pH Aluminum ions make up a large fraction of the cations. As soil pH approaches 4.5 exchangeable Aluminum ions, per se, disappear, and above pH 6 there are few Aluminum ions potentially available.

The table below reports data from a Bordeaux study on the affects of Alumium ions on growth of Cabernet Sauvignon (V. vinifera) grapevines. Note that only 10 ppm (mg/l) in solution reduced vine growth almost in half. The aluminum ions are not absorbed by the roots, and they do not enter the vine. Aluminum ions directly inhibits root growth. Thus aluminum toxicity cannot be detected from petiole mineral element analysis. Vine roots must be inspected.

Effect of aluminum ion concentration in a liquid culture medium on growth of potted grapevines
Aluminium Ion Concentration (mg/l)	Cane Growth Vine (g)
0	743
10	360
200	57
Source: Delmas, Pont-de-la-Maye, 1984

The table below shows that the addition of lime to an acid soil raises the pH and decreases aluminum availability

Copper Toxicity

Copper becomes more available at low pH. For world viticulture, copper toxicity is most commonly associated with long term application of copper fungicides to acid soils. This is one reason that a dependence on copper fungicides to control disease is undesirable.

Other effects of soil pH

Mineral Element Deficiencies: Other elements become less available at low soil pH including:

1. Nitrogen: Primarily because soil bacteria, which release nitrogen from organic matter, grow poorly in low pH conditions.

2. Calcium: Critical tissue concentrations for Ca++ in healthy soils have not been established, but acid soils are, by definition, low in Ca.

3. Magnesium deficiency symptoms are common in vines growing in acid soils. For this reason we recommend using dolomitic lime, which contains a mixture of Mg and Ca ions, to correct the pH of acidic vineyard soils. Mg deficiency is often related to rachis necrosis which has been observed in Long Island and Chautauqua counties.

4 Manganese deficiency has sometimes been observed on high lime soils in the Finger Lakes. French/American hybrid varietes are more sensitive.

5. Phosphorous becomes insoluble at low pH. Very few studies have shown a benefit from fertilization with P. Raising the soil pH makes P available and also can correct other mineral nutrient availability problems cited herein.

6. Potassium availability is theoretically reduced at low pH, however, vines growing in acid soils tend to have excessive K in the foliage and fruit. The high fruit K concentration results in high pH musts which produce unbalanced, unstable wines.

Note that soil pH affects the availability of many mineral elements. A pH of 6 to 7 ensures a good supply of most elements. The exceptions are Fe, Mn, Zn, Cu and Co. Most plants have developed means to solublelize these elements at moderate pH values. Native American Grapevines are an exception in that iron is less available when soil pH is above 6. Vines growing in low pH soil can be expected to show deficiencies of Ca, Mg, P and K.

Correcting acid soils.

The pH and the cation exchange capacity (CEC) of the soil are used to calculate the amount of limestone needed to change the pH of a particular soil. These values are obtained from standard soil tests. Because grapevines require a balance between calcium, magnesium and pottasium, the best method of amelioration is to raise the soil pH using dolomitic limestone which contains both magnesium and calcium ions. Because of reduced K availability, potassium may need to be added simultaneously with Mg and Ca. In addition to the chemical nature of lime, the fineness is also important. Finely divided limestone will exert its effect much more quickly than more coarsly ground material.

Because root growth is inhibited by low soil pH, rooting depth may be determined by the depth to which the soil pH has been altered. Research in other places suggests that deep incorporation of limestone before planting can be very beneficial. Our experience is that surface applied limestone will alter subsoil pH, but only after several years. Deep injection of limestone to existing vineyards has been proposed, but to my knowledge, has not yet been shown to be beneficial.

III. New York experience with acid soils

Low pH Nutrient Imbalance Symptoms of Different Grape Varieties Growing in a Low pH Soil at Fredonia, New York (Symptoms of Third Year Growth)
Variety	Cane Pruning Wt (lb)/Vine	Low pH Symptoms*
Cabernet Sauvignon Delaware Seyval	2.0 a 4.0 bc 0.8 b	0.3 e 1.0 e 1.2 d
Sauvignon blanc Gewurztraminer Merlot	0.4 bc 0.4 bc 0.3 bc	2.0 c 2.3 c 2.3 c
Pinot Gris Chardonnay Pinot blanc	0.4 bc 0.4 bc 0.3 ab	2.8 b 2.9 b 3.0 b
Gamay Beaujolais (Pinot noir) White Riesling	0.4 bc 1.0 ab	4.0 a 3.8 a
*Symptoms 1 = none 5 = Severe Necrosis Delaware is a Native American Variety and Seyval a Hybrid

Varieties:

In regional tests of vinifera varieties across NY, we found an association between the soils in the area where a variety originated and a European variety's tolerance to acid soil conditions in New York. Specifically, Bordeaux varieties (gravelly, acid soils are found in Bordeaux) showed fewer nutrient imbalance symptoms than varieties which, in Europe, are grown in moderate to high lime soils (Germany, Champagne and Burgundy varieties). However, this tolerance is only relative. Tolerant vines grew better than non-tolerant, but still produced musts with excessive K and pH.

Rootstocks:

Effect of Rootstock on Acid Soil Nutrient Imbalance Symptoms of White Riesling Vines in the Third Growing Season, Vineyard Laboratory, Fredonia
White Riesling grafted to:	Cane Pruning Wt. /Vine (lb)	Low pH Symptoms*
Elvira (Labrusca)	0.5 bc	2.3 c
5C	0.9 ab	2.8 cd
Own (White Risling)	0.5 bc	3.1 bc
C 1616E	0.5 bc	3.1 bc
5BB	1.0 a	3.4 bc
Mgt 101-14	0.7 abc	3.6 ab
Couderc 3309	0.5 c	4.2 a
* 1 = None 5 = Defoliated

Vines growing on Elvira (an acid tolerant native variety) and 5C produced fewer symptoms, while C. 3309 and MgT 101-14 produced most symptoms. However, growth and winter survival were reduced by low soil pH regardless of rootstock. A rootstock designed to be more tolerant of acid soils, Gravsec, has been bred by the French national agricultural research station in Bordeaux (INRA station at Pont-de-la-Maye). It may soon be available commercially in the US.

Vinifera varieties are less tolerant of low pH soil than are American varieties. Vinifera vines growing in acid soil show poor growth, low winter hardiness and leaf symptoms of nutrient imbalance. They produce musts high in K and pH. Although limited tolerance to low soil pH has been established for some varieties and rootstocks, correcting the soil pH with dolomitic limestone is the best long term solution. The best time to do this correction is before the vineyard is planted. In such cases, deep incorporation should be considered.

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