Name: LODI RULES COMMITTEE MEETING
Start: 2024-05-06T12:00:00-07:00
End: 2024-05-06T14:00:00-07:00
Location: Lodi Winegrape Commission

MONDAY, APRIL 24, 2023. BY STAN GRANT, VITICULTURIST.

Continued from TOO MUCH WATER & NOT ENOUGH AIR: WATERLOGGED VINEYARD SOILS PT 1.

MANAGEMENT ACTIONS FOR EXCESSIVE SOIL MOISTURE – PREPLANT

As with most soil management goals, it is best to take steps to promote aeration before planting a vineyard. This includes actions to enhance water infiltration through soil surfaces, internal soil permeability to air and water, and subsurface drainage.

Preplant deep ripping or slip plowing is highly effective for disrupting and neutralizing hardpans and claypans, respectively, thereby assuring unrestricted subsurface drainage. Simultaneous deep incorporation of organic amendments further improves the permeability of most soils, while gypsum improves those containing excessive sodium and some with excessive magnesium. Deep cultivation also alleviates topsoil compaction.

Where high water tables persist into the growing season, peripheral ditches alone are sometimes sufficient to ensure adequate root zone drainage and aeration (Figure 1).

Fig. 1. A high capacity drainage ditch between two vineyards. (Photo source: Progressive Viticulture©)

Figure 1. A high-capacity drainage ditch between two vineyards. (Photo source: Progressive Viticulture©)

This applies to some small vineyards, narrow vineyards, and vineyards where in-season water tables infrequently intrude into root zones. Pumping water out of ditches lowers the pressure within them, creating a pressure gradient that pulls water out of adjacent soils and draws air behind them through soil surfaces. Drain water is deposited into an empty channel or another watercourse.

Figure 2. (A) Mechanized equipment for tile drain installation (without front-mounted hose reel and gravel hopper) and (B) the closed trench following tile drain installation. (Photo source: Progressive Viticulture©)

In some cases, adequate root zone drainage and aeration requires tile drains spaced at appropriate depths and intervals across the vineyard. Early tile drain systems involved clay pipes, hence the name “tile” drains. Modern systems consist of fabric-covered perforated plastic pipe, at least 4 inches in diameter, enveloped in gravel (Figure 2). Tile drains function somewhat like underground ditches, using pumps to pull water from nearby soils into the pipes. The extent of vertical water drawdown increases as pipes are placed deeper and spaced closer together (Figure 3). Tile drains are usually the best option for draining root zones of water from artesian springs and water that collects in depressions within vineyards.

Figure 3. (A) A tile drain system cross-section, where the minimum depth of water table drawdown is a function of drainpipe depth and spacing, and (B) the discharge from an operating tile drain system. (Photo source: Progressive Viticulture©)

Wherever there is a risk of waterlogging, plant vines on berms. These narrow ridges centered under vine rows facilitate early soil warming and drainage. Further, berm soils are better aerated than the vineyard soils outside of them. As such, berms are favorable environments for the bases of vine trunks (crowns) and roots.

Select a rootstock known to impart some degree of tolerance of excess soil moisture to grapevines, such as Schwarzmann, 1616C, SO4, and Riparia Gloire. Conversely, avoid rootstocks considered low in tolerance to wet soils, including 99R, 140R, 101-14, and St. George.

MANAGEMENT ACTIONS FOR EXCESSIVE SOIL MOISTURE – POST PLANT

After planting, strive to maintain high root zone infiltration rates and permeability with cover crops, regular organic matter additions, periodic tillage, and, where appropriate, gypsum applications.

When root zones become saturated, take measures to minimize grapevine stress. Ensure drainage systems are operating to pull air or, at least, aerated water into and spent water out of root zones. Similarly, pump flood waters to ensure their continued movement and capacity for gas exchange.

Apply materials to grapevine foliage to compensate for compromised roots due to waterlogging. Where vineyards are inaccessible to tracklayer tractors and sprayers with flotation tires, utilize aerial applicators. Consider applications of readily assimilable nitrogen, phosphorus, potassium, and micronutrients, as well as the hormones cytokinins and gibberellins. In some instances, the combination of low biuret urea, dipotassium phosphate, a complete micronutrient fertilizer, and seaweed extracts rich in hormones has elicited positive responses from vines on waterlogged soils.

After the excess water has drained from formerly waterlogged soils, apply fertilizer to revitalize roots. Some fertilizers designed for this purpose contain a little ammonium nitrogen, abundant phosphorus, and stimulating materials, such as organic acids. Disrupted microbial activity and diminished mineral nutrient availability in recently waterlogged soils may increase the need for fertilizer applications during the remainder of the growing season.

After an extended period of waterlogging, apply liquid organic soil amendments and microbial inoculants through drip irrigation to enhance the recovery of soil microbial communities and their beneficial activities in vine row soils. After harvest, consider applying and incorporating an organic amendment in the tractor rows to facilitate the comeback of soil microbes more broadly across the vineyard.

TO SUMMARIZE

A deficit of oxygen is the primary stress factor for grapevines and microorganisms in waterlogged soils. Waterlogging injury to vines develops sequentially over several days, becoming increasingly severe with time. Detrimental waterlogging effects include reduced root growth and function, decreased uptake and transport of water and mineral nutrients through roots, declining photosynthesis and leaf health, and the formation and accumulation of toxic substances in soils and vines. Avoiding or at least minimizing waterlogging injuries involves pre-plant and consistent post-management actions (Figure 4).

Fig. 7. A successful vineyard on a soil prone to waterlogging, where the keys to success include a well-designed tile drain system, berms, a rootstock with wet soil tolerance, and careful management. (Photo source: Progressive Viticulture©)

Figure 4. A successful vineyard on soil prone to waterlogging, where the keys to success include a well-designed tile drain system, berms, a rootstock with wet soil tolerance, and careful management. (Photo source: Progressive Viticulture©)

A version of this article was originally published in the Mid Valley Agricultural Services November 2010 newsletter and was updated for this blog post.

TOO MUCH WATER & NOT ENOUGH AIR: WATERLOGGED VINEYARD SOILS PT 2

MANAGEMENT ACTIONS FOR EXCESSIVE SOIL MOISTURE – PREPLANT

MANAGEMENT ACTIONS FOR EXCESSIVE SOIL MOISTURE – POST PLANT

TO SUMMARIZE

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