By: Alyssa L. Ochs
Soil protection practices help prevent erosion, improve grape quality, improve crop yield and aid environmental conservation. To practice sustainability and maintain a profitable business, it is necessary to find a balance between soil conservation and water consumption. Also relevant to the soil, fertilizer can make a big difference when growing grapes. Yet fertilizers, pesticides and herbicides have a way of attaching themselves to soil particles and moving from vineyard lands to nearby waterways. Therefore, it’s essential to choose your fertilizer products wisely and always use them as directed to maintain soil health and do your part to protect the environment.
Soil in the Vineyard
Many issues affect the soil in vineyards across the country, including low nutrients, water flow and surface runoff. Gully, sheet and rill erosion are common in vineyards, as well as issues with slope length and steepness for drainage. From one vineyard to the next, variables to consider are crop rotation practices, the amount of rainfall and the type of soil in the region. Increasingly, vineyard operators feel the effects of climate change as they take care of the soil on their land and the grapes growing on it. This often comes in the form of more extended drought periods, consistently higher temperatures, longer hot seasons and increased wildfire risks.
“Compaction from equipment driving through vineyards along the same tracks year after year can severely stunt vine root growth, which will, in turn, stunt vine growth, regardless of how much fertilizer gets thrown on the vines,” said Dr. Jodi Creasap
Gee, Ph.D., BioSafe Systems’ assistant plant pathologist, viticulturist and technical sales representative for the Northeast. Since 1998, BioSafe Systems has been an innovator in environmentally sustainable practices and products to protect crops, water and operations in diverse industries. “In vineyards
where soil is already compacted or likely to be compacted, some growers may use a cover crop that develops deep taproots, such as a radish, which can break up the top six-to-eight-inch layers of soil.”
Dr. Creasap Gee also told The Grapevine Magazine that soil pH could change dramatically in vineyards where workers apply fertilizer without regard for actual soil content.
“Most grapevines require a soil pH between 5-7 for optimal uptake of nutrients from the soil, so in many vineyard sites, managing the soil pH is the most critical part of managing vineyard nutrients,” Dr. Creasap Gee said. “Therefore, consistent soil and petiole testing are so important. You need to know what’s going on in the soil, as well as what’s being taken up by the vines to monitor their health, like the blood tests we humans get during our annual physicals. In established vineyards, applications of nitrogen can reduce soil pH, leading to acidic soils and reducing nutrient uptake in the vines. Consequently, applications of lime may be necessary to improve the soil pH, and, as that will take time to affect soil pH, foliar feeds or foliar applications of fertilizers may be necessary. One of our products, CalOx FT, moves calcium through the vines with your chosen foliar feed product. CalOx FT uses ion channels to move calcium ions through the symplastic pathway, which is much faster than the typical apoplastic pathway. Applied as a foliar application, TerraGrow Liquid can improve vine health and bolster vine stress responses.”
Using Fertilizer in the Vineyard
Everyone who runs a vineyard has a favorite type of fertilizer to use on the soil, such as the manure of cows, poultry or rabbits. Vineyards use urea, zinc, potassium and ammonium nitrate depending on the soil needs. It is a widespread practice to apply granular fertilizer as a broadcast over the vine rows.
As a family-owned manufacturer of biodegradable crop protection, water treatment and sanitation products, BioSafe Systems offers a soil health program called “Sustainable Soils,” which workers can incorporate into any vineyard with irrigation and vineyards before planting.
“Typically, vineyards in the eastern part of the United States do not have any irrigation, save, perhaps, for newly planted vineyards,” said Dr. Creasap Gee. “On the west coast, however, irrigation may be more commonplace, which is where our TerraGrow Liquid plant growth promoter would shine. This product boasts several beneficial microorganisms and can improve plant health. It has been used as a root dip in vineyards to give vines the best possible start as they get established in the vineyard.”
Dr. Creasap Gee said that what sets BioSafe apart from the alternatives on the market is that its products are American-made and produced under strict quality control guidelines to ensure consistency and quality for growers. She also said that BioSafe’s sales representatives work closely with end users and distributors to ensure the optimal use of BioSafe Systems’ products and to answer queries as they arise.
Ideas for Vineyard Soil Conservation
Vineyards can improve their soil conservation practices in various ways, such as using buffer strips, drainage tiles and diversion ditches. It is also possible to protect your grapevines’ precious soil with a specific vineyard layout, permanent sod, and water and sediment control strategies. Mulch, seeded cover crops, soil biodiversity and weed management are other ways to ensure healthy soil for the current crop and for many years to come.
Dr. Creasap Gee told The Grapevine Magazine that the most critical step in this process is to work with a soil and water conservation specialist to identify and correct issues within the site.
“There are many soil conservation practices available to growers, and eXtension lays out a fantastic guideline for soil management,” she said. “Remember, if you don’t have good soil, the vines will struggle to establish good root systems, and without a good root system, vines may be puny and fail to ripen fruit consistently year after year.”
Overall, Dr. Creasap Gee said that the options for soil protection and conservation are numerous, depending on the site and that the options start with soil testing and a site evaluation for water drainage.
“For established vineyards, cover crops, like rye, can be an effective strategy to manage soil erosion and to increase soil organic matter,” she said. “The cover crops are burned down with a contact herbicide, like AXXE Broad Spectrum Herbicide, which can also be used in a vineyard to manage insect pests on cover crops and allowed to remain in the row middles to suppress additional weed growth.”
Fertilizer Tips for Vineyards
As a general rule and for optimal growth, it is best to aim for a soil Ph of about 5.5 to 7.0. Start by conducting a soil test to determine the best fertilizer strategy. Use fertilizer before planting, apply as little of the product as possible to start and introduce it lightly during the second year of growth.
Many vineyards apply a quarter-pound or less of 10-10-10 fertilizer in a circle around the plants and about four feet from the vines. In the years that follow, vineyards often increase the application to one pound but extend the circle to approximately eight feet from the plants’ bases for vines that appear to need an extra boost. Overall, saving more fertilizing activities for spring is best while minimizing usage in the fall season. However, a vineyard may choose to apply fertilizer in the fall because it is easier with the ground being dry but not yet frozen. In the spring, vineyards in some parts of the country may still present challenges due to melting snow and the frozen ground. Grapes are most depleted of nutrients right after harvest and in the early spring, so a combination of fertilizer sessions may be optimal for balance and longevity in the vineyard.
Dr. Creasap Gee emphasized how important timing is when using fertilizer in a vineyard and always to be sure to apply fertilizers when the vines can take them up.
“For example, we know that soil nitrogen can be taken up by roots during a two-week window around bloom,” she said. “The recommendation from extension programs is to apply nitrogen in split applications: once two weeks prior to bloom – and only what you need, hence the soil and petiole tests mentioned above – and again after bloom but before veraison.”
She also emphasized how necessary testing is because testing your vine tissues and soils on a regular basis will ensure that you don’t harvest your vineyard nutrients with your grapes and without annual, consistent inputs.
“Remember that the micro- and macro-nutrients in the soils are only part of the equation,” Dr. Creasap Gee said. “The microbial activity in the soil is what makes these nutrients available to root systems, so ensuring a soil with high organic matter and a diversity of microbes can only improve overall vine health.”
A final piece of advice that Dr. Creasap Gee offered is not to be afraid to ask for help because plenty of specialists around the country can assist you with vineyard soil management.
“You don’t have to rely on the internet. You can reach out to any of the hundreds of viticulture specialists around the world who would be more than happy to help you strategize and problem-solve.”