Fertilizer: it's elemental.
For viticulturists, the correct application of fertilizers means more than a quick reference to a seed packet or the Sunset garden guide. Fortunately, there are experts in the field. I conferred with farm advisors in four different growing areas to learn about current best practices for this agricultural basic.
First, though, I checked out my trusty Lodi Winegrower's Workbook to see what it had to say. Disconcertingly, it does not contain a chapter on fertilizer. Rather, I found the subject under the heading "Soil Management," where it bluntly states, "Basing fertilizer and soil amendment application decisions on soil and plant monitoring is basic economics.... Every grower should be able to make informed decisions about fertilizers and soil amendments." But, the workbook cautions, "Soil tests are not reliable for determining fertilizer requirements."
Regular petiole samples at time of bloom are, therefore, the recommended basis for determining the need for fertilizer, although, if vines are sprayed before sampling, lab results will be invalid. And, the workbook continues, "If the vines have high vigor, they do not need nitrogen, regardless of the tissue samples."
All fertilizes, including so-called "chemical fertilizers," are formulated of substances appearing on that science class essential, the periodic table of the elements. Nitrogen (N) is the most basic and ubiquitous fertilizer applied in commercial agriculture. "We recommend that growers apply only enough nitrogen to keep the vines green and at a vigor level that will give them good quality," says Maxwell Norton, UC Extension farm advisor in Merced. "I recommend they use the cheapest form of N they can find, unless there are considerations about pH."
Mark Longstroth, district extension horticulture and marketing agent for Michigan State University in Paw Paw, adds, "I do not recommend brands....Growers buy their bulk fertilizers from local bulk distributorships. I have told growers that there is no difference in the nitrogen forms, and they should buy the nitrogen fertilizer that is cheapest per pound. For example, urea (46-0-0) at $300 per ton costs $0.326 per pound of nitrogen. This is the cheapest form."
Longstroth points out that bulk dealers often market "house blends," which incorporate large percentages of other chemicals, including phosphorous (P). "I do not recommend blends, because most growers do not need phosphorus." Not only are blends needlessly expensive, and phosphorus often unnecessary, P can create algal increases in surface water caused by over-enrichment (eutrophication). With water availability and quality a continuing concern everywhere, any type of pollution is something to be avoided. The government now restricts application of P where the soil has more than 150 ppm, a good incentive to perform soil tests.
Potassium (K) is the other basic fertilizer ingredient, frequently applied as potash (KC1). "If applying potassium, (growers) need to evaluate chloride hazard before using KC1," Maxwell Norton warns. Longstroth frequently recommends KC1 for his Michigan growers, but "only if soil level is less than 150 ppm. Many growers put it on annually because they know they need it.
"Some growers soil sample to determine fertilizer needs," Longstroth says, "I would prefer that they do a petiole sample in summer at about veraison to determine what the plant needs are, and not fertilize by what is available in the soil. Most growers do not sample at all."
A pity, that, because, like anything else in the vineyard, using even the least expensive chemicals can be costly: as much as $100 per acre. "None of the winegrape growers pour it on like the juice grape guys, who do $0 to $250 an acre, like they are growing corn," Longstroth notes. This spring, he advised growers to cut back on nitrogen, because they have had light crops for the last two years and the vines are sufficiently vigorous.
In Indiana, "Nitrogen is applied in spring about two to four weeks after budbreak. Many growers apply half then and the second half about four weeks later. Care must be taken not to apply urea during bloom, as it can reduce fruit set," says Bruce Bordelon, associate professor of horticulture at Purdue University. Recently, however, "Recommended N applications have been delayed from what we used to recommend, based on research done in Michigan that shows that plants take up little applied N until about bloom time, making early season (budbreak) applications wasteful and environmentally irresponsible."
"Overall, we may be adding slightly less nitrogen to vineyards, as we better understand the relationship between nutrient management and wine quality," says Robert Stevens, extension soil scientist with Washington State University at Prosser, in the thriving Eastern Washington wine country. "We are currently doing research to determine appropriate nitrogen rates for different grape varietals. The industry definitely uses different nitrogen rates for different varietals.
"The trend is to manage each vineyard and varietal to fit the site, growing conditions and the winery requirements for wine to be produced," Stevens says. "There does appear to be a small increase in organic production, with its additional challenges for nutrient management."
Stevens was the only advisor who reported a growth in organic practices. Have you noticed a trend toward organic? I asked. "Nope," Longstroth said. "Not particularly," Bordelon replied. "There is not growth in the organic industry" Norton stated.
Are these chemicals safe? "I have concerns about over-application and loss of material and money from run-off and leaching," Longstroth said.
Bordelon expressed no safety concerns, "other than storage and handling of corrosive materials--especially ammonium nitrate. Growers should have adequate facilities to store materials if they keep a supply on hand," he cautioned.
In general, though, with proper analyses and thoughtful application, the advisors agreed that, "chemical vineyard fertilizers are very safe chemicals," as Stevens put it. "As with all chemicals, they must be handled with proper practices. The amounts of fertilizers used in vineyards are very small compared to other crops, and with proper irrigation practices, do not pose a significant potential to harm the environment. With proper application rate, placement and timing, fertilizers are very effective."
A study by Fabrice DeClerck and Michael J. Singer published in the April-June 2003 edition of California Agriculture indicates that, in California soils at least, "chemical quality has not decreased significantly over the past 60 years." Although plant-available phosphorus in both the San Joaquin Valley and "Wine Country" (sic) grew significantly, it remains at about half the regulatory level of 150 ppm. In the same growing areas, however, nitrogen levels soared from well under .2% to .8% in Wine Country and almost 1.4% in the upper San Joaquin.
At least to these untutored green eyes, this trend seems like something to watch carefully.
RELATED ARTICLE: Fertrell: Green Before Its Time
Most people probably think of organic farming as a relative newcomer to the American scene, an outgrowth the 1960s counterculture. Not the people at The Fertrell Company of Bainbridge, Pa., which has been producing organic fertilizers and soil conditioners since 1946, long before the concept of organic certification even existed. It is the oldest organic plant food blender in the United States.
For growers who are considering the lengthy and costly switch to organic methods, the mission statement in Fertrell's 2003 catalog may be of inspiration. "Sustainable Agriculture--More Than Just Good Farming," it begins.
"Today, we have realized the earth has limits to our pillaging, and it is time for man to reexamine his relationship with the living foundation on which he is standing. As modern day farmers, we must realize we are working with an ancient life form that deserves our respect," it continues. "Everything a farmer does affects him, his family, his neighbor, his community and this planet. It really is all interrelated; the earth is one living organism."
Obviously, the people at Fertrell have given the issue lots of thought. According to president David Mattocks, "We offer total sustainable programs for vineyard production. All nutrients are provided in our blends: nitrogen, phosphorus, potassium and trace elements."
Despite the fact that, "Governmental controls have become more of a factor in most situations, there are no known situations where our blends cannot be used," he says. Many Fertrell vineyard products are certified for organic production.
Like the farm advisors in the accompanying article, Mattocks recommends testing soils and plant tissues to determine actual nutrient needs in the vineyard. In recent years, he says, fertilizer use has "become more specific to crops being grown and to the regions where they are growing."
Of the myriad Fertrell products and blends, Mattocks singled out a few specifically suited for commercial vineyard use: Greensand, which amends the soil to hold nutrients and moisture during dry seasons; the Super N 4-2-4 certifiable organic fertilizer blends and Foliar Feed Liquid Fertrell #3, a kelp and fish blend which is filtered and can be added to liquid fertilizer systems. Fertrell also distributes Engelhard Corp.'s Surround crop protectant, described in the April, 2003 issue of Wines & Vines.
The company has hundreds of distributors in most U.S. states. California clients are served by dealers in Oregon and Washington. For more information, phone (717) 367-2566 or visit the Web site fertrell.com.
Rep. Radanovich Leaves Industry
Five-term California Congress man George Radanovich (R-Mariposa County) has closed his family winery and is selling off its assets to pay debts.
Radanovich introduced grape-growing to Mariposa County in 1982, and four years later opened the region's first winery. As the first professional winemaker to serve in Congress, he received national publicity, and has been a staunch supporter of the grape and wine industry throughout his term in office. He is co-chairman of the Congressional Wine Caucus, one of the largest on Capitol Hill.
Radanovich, said to be contemplating a run against Senator Barbara Boxer in 2004, expressed regrets about the failure of his 4,000-case-per-year winery. "It's been the worst six months of my life," he told the Modesto Bee.
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|Title Annotation:||related article: Fertrell: Green Before Its Time|
|Publication:||Wines & Vines|
|Date:||Jun 1, 2003|
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