Dry farming

[Tatiana]

We have about total of 350 vines of Cabernet , merlot, Zinfandel and Chardonnay . It is 3 years old small vineyard in Vista, CA. I have been using dripping style of irrigation since we planted the vines in clay type soil, sunny and breathy hilly site . The vines are doing great and ready to give us a beautiful first crop. I would like to switch slowly to dry farming . When should I start: before the harvest or after?

 

[Tatiana]

I want to add a few more details about our vineyard in addition to my previously placed question about dry farming:
1.The distance between the grapes is 8 feet by 8 feet
2. Clay soil, slightly hilly, breezy site
3. Annual rainfall is about 13,7 inch
4. The grapes are 3 years old ( cab, merlot, zin and chad )

 

[Julie]

I merged your two threads together, having two threads on the same subject can get a little confusing.

 

[Deezil]

To go from drip irrigation to dry farming, you're going to have to change some things, and it's going to have to happen over time.

Dont remove your irrigation equipment yet though, but you do need to start stressing the vines next year. And I dont know how much of a crop you can expect, during the conversion.. So take that in mind..

Basically, what you need to do is not water next spring. The vines arent going to look pretty at some point in late spring / early summer, and you'll probably have to water, but the point is to only water enough to keep the plants alive, not thriving nor perfect.

If the vines look healthy and perfect, its because they're getting all the water they need from you still & you arent allowing them to dry out some, which makes them search and tap deeper into the ground, searching for its own source of water.

Do this all long enough, and some year you wont have to turn the water on

They've drilled wells down 60-80ft and pulled grape roots out of the core from the drilling, at those depths.. So if theres water to be found, the grapes will do it. You just have to stress them enough, for long enough, to find it... How long that could take is anyones guess unless you dig deeper into your local topography and find out how deep down surface water is, how deep your soil bed is to bedrock, etc etc

Thats the basics, anywho.. You may consider some sort of cover crop to help the soil retain water - its better if the sun is frying some small plant instead of baking the moisture right out of the top layer of soil.

There's lots of information out there on this, even though its kind of on the fringes of the farming community.. Gotta be careful not to buy any of the 'hype' though

 

[Tatiana]

Thank you for taking time to reply to me. I did a lots of research about dry farming lately. I am very interested to gradually switch but unfortunately I have a few obstacles .
Our root system is not a drought tolerant kind, as I found out from our supplier from Nova vines, but a disease resistant one ( 114). Can I still train my grapes to grow deeper roots in order to search for their own water ? Our supplier said that 114 roots do not grow as deep for example as St. George kind, but it is a strong root system.

And there is one more thing. We leave close to a nursery . Sometimes their water runs towards our property. Will it stop my grapes from growing deeper? Or will this extra a little bit of water will make them settle down at a shallower soil? As I mentioned before, our soil is clay and gets about 13.7 inches of rainfall per year. I am also using drip irrigation about once a week in order to keep the grapes happy during the first 3 years of growth . Whatever I did ( including CA puppies ground cover) made my grapes look very healthy and beautifully productive on the 3 year. But my water bill is not pretty! It is time to make a few changes around here!

I am waiting for your thoughts about my questions . And, thank you very much in advance!
Tatiana

 

[Deezil]

I've been reading on dry-farming myself for about a year, but I'm by-no-means, an expert. Just trying to help.

The depth of your roots, and whether or not it's going to work, is going to depend on how far down your water table is. If the roots only go 15-20ft down but your water table is 80ft down - you see the problem.

I cant remember if that information is on the Soil Survey system or not, but even if its not theres good info about the content of the soil, on that system.

You mention having clay soil, which means it probably drains okay but wont retain moisture & that 13.7 inches of rainfall you see, probably runs right away after making the surface mucky for a bit. Might consider growing some alfalfa as a cover crop - just recently learned that their roots go deep as well (15-20ft), and when they die, those tap roots diminish and end up as organic matter in the soil, increasing water retention over time

The nursery... Kinda worrisome, but thats because I cant lay eyes on it like you can. The water - that might slow your process down for the vines that the water drains closest to... The bigger problem i'd have is whats IN the water... Fertilizer, pesticides, etc? No way to know unless you talk to them

If you're not pushing for your first harvest this year, you could try to take the first step soon - go from drip irrigation every week to every other week.. The vines will react some, but they shouldnt die

This could take a few years to get you to the point where you cant remove the drip irrigation, but the water bill should start to lower atleast

 

[Tatiana]

I am not worried as much about the nursery water run off ( I do not think they lose a lot ) as I worry about my grapes not be able to grow deep enough to find " China".
I will start with the Soil Survey !
About the cover crop . We already have CA puppies that bloom beautifully during spring , die out in the summer and come back again next year. I can try alfa too. Why not, more cover is better!
I read recently that it is very important to till the soil as often as possible in dry farming method. But what about the ground cover? It would get destroyed if I disturb it every, lets say, two weeks .
The bottom line , if there is no water under 20 feet or so, my dry farming idea will go to rest until I plant more drought tolerant grapes such as st. George . But I still can train my current grapes to be better survivors with a thicker skin !
Live and learn !
Thanks for chatting with me . It really helped !

Tatiana

 

[Deezil]

Tilling is kind of controversial. There's a few approaches.

There's the 'modern' tilling practices, which it seems like you've been reading of - these involve discing the ground, which does a few things; it will interrupt the life cycle of weeds growing between the rows, it'll also break the surface-roots ( i cant remember the real name right now; i always seem to respond to this when im not awake ) of the grape plants themselves which is "good" for the grape plants as it makes them put more energy into repairing their roots and this can somewhat slow down their green-growth vigor. The problem with tilling, is soil erosion and abundant loss of soil vigor / nutrients. See, the people that till, also "probably" use chemical fertilizers - nothing wrong with it if thats your approach, but they pretty much HAVE to use chemical fertilizers because the soil cant sustain itself with the erosion (winds, with no shallow roots to hold the soil in place) and baking that the sun gives it (breaks down the nutrients faster)

And there's "Green Manure". These are crops like alfalfa, which fix nitrogen from the atmosphere and put it back in the soil (most plants feed on nitrogen, so this is opposite).. These are usually left alone until after they flower but before they seed, when they are either mowed/scythed/eaten down; sometimes these are tilled under but its very common to find this set up in till-less operations.

In a till-less operation, its mowed down and left to degrade right where it fell. Some people employ/keep sheep or something of that nature, but if you went that route I'd suggest just having them come by for a week and not try to jump the hurdles of keeping them yourself. They eat the cover crop, deposit their "goodness" and move on. This is one approach that helps to work away from chemical fertilizers.

This can easily (in your head) work your approach towards something of an organic/bio-dynamic approach, which isnt easy to pull off but I happen to believe in (dunno about all them bio-dynamic practices, but the idea/theory of it is honorable)

When you're reading, be careful to diagnose the slant of the authors - most either support chemical fertilizer or organic/bio-dynamic practices. It's all good, relevant, and correct info. But if you take information from one system and try to work it into the other, its headaches and heartaches with a large dose of confusion until it gets straightened out. Not to say you cant mix the two approaches, to a certain extent, but like you've already found - how does one grow a cover crop if you till every 2 weeks? You dont

I dont remember exactly how far down 114 will go, i just spouted 20ft as an example in my stupor; a little investigation can answer that definitively for you though.

Glad to help, hopefully I didnt just confuse you

 

[Tatiana]

Oh no, no confusion at all ! I have a better picture now. You gave me a lot of information and answered a few questions on some things that I could not make sense off.
I will try to find out how far 114 roots go and how deep our " gold" is hidden ( water).
We just tilted the soil ( 2-4 inches) yesterday before I got your responds . I do not think it did any damage to our grapes . The cover crop of CA poppies died out in May and the soil was standing bare being baked by the sun since then . Hopefully , a little air will cool it off .
Ok, I guess I am still a bit confused .
Can I combine two approaches ( a little tilting when it is needed, a cover crop when is blooming and some aged horse manure once a year) ?
I liked the idea of disturbing the shallow roots in order to stop the grapes from becoming a "tropical forest ". I had to trim them twice this season . They are very happy campers here ( yummy water, a lots sun , ocean breeze and a dedicated russian woman, babysitting their roots ) . But I have to admit , my grapes paid the rent on the third year of growth . I am going to get a gorgeous crop this year ! The bunches are huge and uniformed on every vine!
Well, enough of bragging . Thanks again and again for sharing your brain sells with me . It is more interesting to chat with a person then to read a bunch of information on the net. Please, tell me more of what you know about growing the grapes. I am still a beginner.

P/s I changed my profile picture so you can see my cover crop of poppies in march . Do you still think I should change it to alfalfa ?

 

[Tatiana]

I found this info today. I thought you would be interested. • Sorry for messed up copy/ paste style. I tried my best but my computer was fighting me today.

Influenceofsoilphysicalproperties.Fine-texturedsoilshavehigherwater-holdingcapacitiesand shallower infiltration rates than coarse-textured soils, and so, one would predict that roots in fine-textured soils would be smaller and shallower. Still, a clear correlation between texture and horizontal or vertical spreads has not been found. One author reported that root densities were low in the top 20 cm of sandy soils (coarse-textured). This might give the impression of a deeper root behavior in this type of soil. But the authors offer an alternative explanation: rapid drying and extreme temperatures may be shortening root lifespan in this type of soils. Overall, the studies reviewed point out that soil structure, stoniness, and depth of the water table were the key determinants of vertical root distribution, regardless of genotype or of texture. It is generally accepted that soil depth is the most important factor determining root depth distribution.
• Influenceofculturalpractices.Consistentlythroughoutthestudies,cleancultivationthroughtillage, and the establishment of a permanent cover crop, diminished root presence in the upper 20-30 cm of soil. Root pruning and root competition, respectively, are likely the mechanisms involved. Inversely, minimum tillage practices, mulches, plastic covers, and herbicides, all increased grapevine root densitie s in the upper 20 cm. One author studied the influence of deep plowing, or ripping, on root depth, but unfortunately, the study was inconclusive.
• Attheend,theauthorsnotethatsometimesrootstocksexpectedtohaveshallowroots,didnotactually perform that way in their review. One example was 5C, commonly known to perform well in poorly- drained soils, and so expected to have shallow rooting behavior. In this study, 5C exhibited relatively deep- rooting behavior in most soils where it was examined. Other examples were 420A and 110R, not known as high-vigor rootstocks , yet showing deep root profiles in this review. The authors conclude that, besides root system size, more subtle factors such as root longevity, nutrient absorption capacity, and root density, may be important contributors to differences in scion performance.