When you start something from scratch, you often have to employ a great deal of trial and error in order to find out what works and what doesn’t. In farming, I think this proposition is made even more challenging by the fact that things happen slowly. With the vines for example, if you prune something off that you shouldn’t have, you have to wait a year or more for it to grow back. If you plant a vineyard and then realize that the rows run the wrong way, well, it could cost so much and take so much time to change that you start having these thoughts like; it’s my kid’s problem. But one way or another, you have to press forward. You don’t always have the time to achieve certainty, or to feel like the things that you are about to do are without risk. Sometimes you just got to pull the trigger when your gut says to. Then stand back and watch, or, in my case, realize that you will have your conclusions in a few months or a few years. Such was the process that led me to “bore-hole irrigation.”
This will be the first year that we fully implement this style of irrigation. In other words, this is the first year that we will be putting 4 inches of water on most of the vineyards through the overhead sprinklers, at time in the growing season when most growers would consider it taboo. To fully understand this, let's back up a bit.
When I first started farming, drip irrigation, the process of delivering water to the vines through drip lines, was still sort of new. There were plenty of vineyards out there that were hold outs, and had only the traditional overhead sprinklers. The impetus for drip irrigation is that it’s efficient. It puts water out right at each plant. You don’t water every inch of the ground like you do with sprinklers. There is less evaporation. Thus, you typically end up using less water per acre, which in turn, allows you to water more acres simultaneously. As time went on, I saw a good number of vineyards install drip lines. In some cases it was the only irrigation system they put in. Interest in actually watering one's vines through an overhead system became more and more rare. While we did not remove our overhead system, we too followed the gospel, and installed a drip system.
As time went on, I started to see a few new vineyards installing both systems. Why go back to overhead? The obvious reason is for frost protection. In the spring, after the tender shoots start to push out of the buds, if you get a real cold night, those shoots, and thus your crop, gets whacked. On those nights, if you have overhead sprinklers, you have frost protection. A few more years went by and I also started to see growers become more interested in their cover crop, i.e. the grains or grasses that you grow in middle of the rows between the vines. Drip lines are not going to serve up water to those areas. If you want to irrigate that cover crop, you have to have overhead, or hope that it rains.
While I do like the efficiency of drip irrigation, over the years I started to feel like we were missing something when we used only the drip. For starters, I got tired of nursing the vines. With overhead, while you do have to put on more water per acre each time you water, at least that usually means you can water less often. With drip, because you are delivering the water right to the zone of the vine's roots, you don't want to go overboard and make the vines grow too much. So, you put down less water at any given time. But because of that, the vines tend to run out of water more easily, so you end up watering the vines more frequently, i.e. "nursing" the vines. Every time I run the drippers I have to 1) turn on the pump 2) make sure all the appropriate valves are open/closed 3) send a crew into the field to walk the lines to make sure all the emitters are working and not clogged, etc. While the actual delivery of the water is efficient, doing all this multiple times per year is a hassle.
Another thing with a drip-only approach is that the middles of the rows get real dry. Real dry means real dusty. Now, I am a farmer, so if harvest has to be dusty, so be it. But I started to have these little moments, "What if I put on an inch through the over head a few days before we pick the grapes? Would that screw things up? It sure would take the dust down." Well, no one else was doing it, and in the end it seemed a very risky, so I let it go. Nonetheless, there seemed to be something interesting about it, and in my mind it started having to do with more than just keeping the dust down.
Then a few more years went by. That's when I got religion, the religion of “Terroir.” I started having trouble with the fact that the vines were essentially being invited to grow in the hydration sphere right under the drippers. Then I thought about it some more and my sense of it was that the vines were being forced to grow, and only grow, in that hydration sphere. "But look at all this ground," I would think to myself as I tried to wrap my brain around the issue. "The Terroir is not confined to the dirt under the drippers. The Terroir is all the dirt." That's when I got this idea, “What if I was to put on a sizable irrigation through the sprinklers right at the moment that I considered to be my window of opportunity?” That moment in my mind was veraison. Veraison is the point about 6 to 8 weeks before harvest at which the berries turn soft. In the red varieties, it's also the point at which they get their color. Before veraison there is tremendous mildew pressure in our vineyard. That's probably not a great time to get the vines all wet and cold and make the ground so soggy that you can't get in the field to spray for at least a week. After verasion the issue is bunch rot, and with us always seeing our fair share of that stuff as well, putting down lots of water then did not seem to make much sense either. Besides you don't want too much water too close to harvest for fear of diluting the intensity of the grapes and thus the wines. So, as my old circular logic would tell me, I just have to nurse the vines with the drippers, right? Well, I grew tired of nursing the vines. I also grew tired of the dust. And I was almost to the point of needing a psychiatrist because the vines were not spreading out their feet into all the terrior. I started watering through the sprinklers at veraison.
While I was apprehensive about the potential for rot, my gut still told me that it could not be some wimpy amount. It could not be me second guessing all this because most of my colleagues would think that I was crazy. It had to be enough water so that I didn’t have to water again before harvest. It had to all happen in one night because my theory was, if I stretch it out over 2, 3 or 4 days, then I really am asking for problems. I'd be encouraging some kind mold and I would not be able to get into the field to address it for long time. I had to get 4 inches on and it had to happen in a matter of hours.
It's called bore-hole irrigation because the first time I tried it, we only got about an inch down. Why? Because the nozzles in the sprinklers were not made for farmers like me. They were conventional. They put out a normal amount of water. I told my vineyard manager, Rance Minyard, we needed more flow. So, he took the nozzles to the shop and he bored out the holes. It's funny how I look at stuff like sprinkler nozzles with bigger than normal holes and I think to myself, "It's beautiful."
The days and the weeks after we first tried those nozzles, we saw a number of interesting things. For starters, as you can imagine, the vines loved the big drink. Their shoot tips got perky and they turned a greener shade of green, as if to say, "Thank you." It was as if the vines chugged around third base and started heading for home. Indeed, they needed no more water until after harvest. Maybe it's just me, but I was convinced that they were in better balance than they would have been had they been nursed through the drip system, and my psychology was that the wines would now finally come from the terroir, all the terroir.
Dust? Through harvest, the dust was gone.
Any more benefits? Yes, and this one is very cool. Over the last few years I have become especially interested in my cover crops. At this point I very aggressively farm legumes between the vines. Legumes are nitrogen fixing plants. Peanuts and soy beans are common examples, but there are all kinds of leguminous plants that are capable of taking nitrogen out of the atmosphere and putting it in little nodes in their roots. The keen thing about it is that if you grow a strong stand of legumes and then mow it, it’s like a very natural, non-intrusive, no-till way to fertilize. How does Bore-Hole Irrigation play into it? What I have found is that a Bore-Hole Irrigation at verasion, coupled with another 1-2 inches after we pick, makes the ground perfect for the planting of the cover crop. The legumes then explode into whatever heat is left in the days of September and October. I have always given the vines a drink after we pick. They are usually pretty thirsty by that point, and it used to be a good time to turn on the drippers. But now I look at that point as also being the perfect moment for the planting of my cover crop.
You might think that this is all good because it’s killing two birds with one stone; the vines get their drink and the cover crop gets planted. But it’s actually even more than that. If your cover crop is a legume, you want to mow it at full flower. That's when you get the full bang for the buck in so far as the legumes fixing nitrogen in the roots and thus becoming a nutrient source for the vines, like manure. If you mow the legumes too soon, you don't capture the full nutrient impact.
What's the potential wrench in the gears of my system? Well, if I have a frost problem in the spring, I’ll want to mow my legumes before the problem, because a full stand of legumes will effectively push the cold off of the vineyard floor up into the vines where the new, tender shoots are. By March 1st, before bud break and thus before any frost problems, we want to be able to kill the flowers as we call it. That's our terminology for mowing a healthy, full flowering stand of legumes; the thick thatch from which also helps to keep the dust down during the earlier part of the summer.
You might be thinking, what about the sprinklers, can’t you just turn them on for frost protection? You can, but it has its limits. If it’s really cold, say down in the low 20s, you better hope that your cover is mowed and the cold air is draining out of the field. You might also think, can’t you just plant your cover after the frost season and grow it in the summer? No. You would end up destroying your cover every time the tractors ran over it during that part of the year known as the growing season. The moral of the story is, if you want to mow your legumes at full flower come the end of February, you not only need to get on with planting your cover right after you harvest, you need that cover to grow like gang busters. Now, I am allergic to legumes. Peanuts are my death. I have a hard time grooving on a freshly mowed field of something like Vetch the same way I do a hand full of freshly bored out sprinkler nozzles. Nonetheless, I have been very proud of my thatch lately.
My theory is that some of the water from the bore-hole irrigation is still deep in the fields at the time of harvest. If I put on 1-2 inches of overhead at that point, the vines still get their drink; I can get my tractors back into the fields within a week to plant the cover, which then grows vigorously because the new water in the middle of the rows unites with the old water from the bore-hole irrigation. Overall, the vines seem to love bore-hole irrigation, it’s integrated with killing the flowers in the early spring, and, ultimately, I think it makes better wine.
Being a fan of causality, it is interesting to me how well it all flows. I guess it’s true of a lot of things; when you get the timing down, it flows. I would not say that I am a radical for all this yet because it's still a bit theoretical. I need to look at it fully implemented for a few years to make sure I’m not creating any problems that I don’t yet know about. I think at this point, I hope at this point, that the benefits will out weigh any costs. There was a part of me that did not want to write any of this because of its proprietary nature. While I have heard a few of my colleagues from time to time touch on some of the various aspects of what I have said here, I honestly don’t know anyone who has presented these principles in quite this way. So why do it? Because for me, it’s not about trying to stem the flow of ideas, or attempting to change the supply of good wine out there; something I couldn’t do even if I wanted to. It’s because I want my customers to see it. I want you to have a feel for the reasons and the actions that will always make my stuff good.
Cheers,
Bryan