Fertilizing Vines

[treesaver]

I have been growing grapes now for over 15 years, and have read a lot written about fertilizing vines. Some say to fertilize twice a year with 10-10-10, and others say only if the vine has low vigor. The soil where I live and have my vines is red clay. Good topsoil down about eight inches to a foot, and old red clay that you could make bricks out of on down. I have thought about fertilizing numerous times, but would rather ere on the safe side than overdo this! I would like to hear from some of you that may have similar conditions on what you do. I have been raising good crops, and the leaves appear to show no signs of nutrient problems, but think I should be able to get more yield than what I have been getting.

Thoughts anyone? Thanks in advance, Lee

 

[Stressbaby]

I'll be watching this thread.

I have the same conditions - so much clay here that we actually have brick plants - no joke, they mine the clay and make bricks. Anyway, my vines are just a year old and in the first year some, such as Traminette and Vidal, exhibited tremendous vigor (ie, 6' to the top wire PLUS bilateral 4-8' cordons with spurs) and certainly will not get any fertilizer. The Norton and Chambourcin much less so, I will hit them again this year.

Just wondering, what grapes? What trellising? What sort of pruning do you do?

 

[treesaver]

I have norton, frontenac, concord, and a small number of cataba. I have the norton on gdc and the concord on double kniffen. The rest are on twc. I've had good growth on most vines, but a few I'm sure could use some fertilizer, but I've been scared to overdo it. I also have just one leaf vines of verona, and will fill in the last fifteen spots this spring with somemore verona. Hope for some sound advise, because everything I've found on the subject is always contradictory! I forgot you ask about pruning. I spur prune, mainly because that is all I know and it makes sence to me. Cane pruning is still a little fuzzy for me, haven't studied it enough to want to attempt it! Plus I'm not sure any of the varietys I grow are suited to cane pruning. I'm open to suggestions tho!

 

[wxtrendsguy]

We grow commercially to feed our winery....we add Nitrogen on a yearly basis depending on the vigor we saw in the year prior and or yellowing of the leaves. We have also tried using compost which was also very effective and best of all is time released dosage of nitrogen. Additions are done in the Spring prior to flowering, usually May.

 

[treesaver]

What type of soil are you planted in, wxtrendsguy? I'm sure that soil type would have a lot to do with adding fetilizer.

 

[balatonwine]

Fertilizers, what a vine needs and when is summarized here (note, even this article states there is "some disagreement"):

http://www.spectrumanalytic.com/support/library/pdf/fertilizing_grapes.pdf

I provided the above as a non-biased view. Now on to my opinion.

First consider, there are two types of fertilizer application methods: soil and foliar (you spray the leaves).

Normally, one will fertilize by soil only once a year. Normally in mid winter or the spring. And only if needed. Even so, it is not always easy to know what nutrients your vines needs without proper lab analysis. With or without visible symptoms. For example, chlorosis (yellow leaves) can have many causes, and it is important to diagnose the problem correctly to apply the correct treatment. As an example, various levels of chlorosis can occur due to deficiencies in any one of these:

Nitrogen
Iron
Manganese
Magnesium
Zinc

Or even from non-disease or nutrient issues.

If you want to run by a "rule of thumb" method, applying >=1 year old compost is often sufficient to apply the correct micro-nutrients and limited nitrogen needed by vines. It also improves soil structure. But potassium may still be an issue, depending on your soil.

Foliar sprays are a very good method for applying mid season and micro-nutrient fertilizers (Zn,Mn,Mg, etc). I apply them in the summer. Another benefit to foliar sprays is (1) it is easy and (2) you are only fertilizing your vines, not the weeds in the soil.

There are also other options to fertilize, such as legume aisle cover crops that can supply nitrogen to the vines.

And of course, it depends a lot on your soils. Heavy clay can bind a lot of essential minerals and nutrients, making foliar sprays maybe a better option.

 

[wxtrendsguy]

I should have said he have tested our soils and they have been found to be slightly Nitrogen deficient. We already have far too much Potassium, Phosphorus is in range as is PH and other trace minerals. The recommendation from our cooperative extension agent is to add nitrogen at 70 units per acre.
Our soil is a well drained shale with <12" of shale-loam topsoil. Hence the reason we fertilize in the mid to even late spring. If we were to fertilize in the winter much of it would leach past the root zone or wash off due to copious winter and spring precipitation.

 

[treesaver]

Thank you balontonwine for that. That is helpful! I will look more into foliar spraying, as a more controled way of fertilizing. I put your link in my favorites so I can refer back as needed.

 

[treesaver]

I have been hoping more of you fellas had some imput of what and how you do yours.....anybody?

 

[dwhill40]

I have been hoping more of you fellas had some imput of what and how you do yours.....anybody?

I have Sandy acidic depleted century old farm land. Once cotton field now cow pasture. I remineralized using granite dust and/or azomite both containing up to 4% potassium. With clay you probably don't need to worry about that. I researched mycorrhizae at length and found where superphosphate tweaks a general in the vine turning off the fungii's connection to the roots. I found a reasonable distributor for soft rock phosphate. The price isn't so bad when you multiply it by the years it can last. I'm growing mostly Cab so in the Sandy soil and hot climate vigor is more than ample so I apply nitrogen carefully. I walk down the row middles with bags of black cow compost and shake out a bag about every 40 feet every couple of years. Having acidic soil I limed well at first but pour the gypsum to it to bind up the aluminum uptake. My subsoil was 4.9 and topsoil was 5.2 when I got it tested 5 yes ago. I can stick a shovel in the ground and find an earthworm almost every time. Of course I only have a quarter of an acre so I can manage this less commercial way with ease. Some may argue with my methods but this has damn sure worked well for me in Alabama.

 

[balatonwine]

I have been hoping more of you fellas had some imput of what and how you do yours.....anybody?

Compost. In the rows. Which are kept tilled all season. Aisles have year round cover crop. Mowed. Mostly for erosion control. Promote clover there when found (but that is not much).

Regarding compost: Easiest source is to ask some local farmers with livestock: Some will happily let you come and haul away some of their manure. Even if you have to buy it, it should be cheap. Age it at least a year before applying (yes, good compost is like a good wine -- it needs aging. ). Add in your pressed must in the fall to your compost pile, or spread in rows directly the year it is pressed, turn into the soil that fall or next spring.

 

[Masbustelo]

One word of caution regarding compost in the USA. Agricultural products tend to be heavily contaminated in the US with persistent herbicides. These herbicides take as much as five years to break down in soils. https://compostingcouncil.org/persistent-herbicide-faq/ Grape plants are highly susceptible to these herbicides. The composting process concentrates them when present. If one uses commercially produced compost sadly it is safer because they can be tested and warranted as being safe to use. It's rather a sad state of affairs regarding US ag bi products.

 

[balatonwine]

One word of caution regarding compost in the USA. Agricultural products tend to be heavily contaminated in the US with persistent herbicides.

Excellent, excellent point.

Yes, I forget that not everyone is organic. And the US ag industry is very chemical dependent. I get manure from an organic dairy.