The value of targeting applications with sap analysis

One characteristic of top tier growers is the desire to make decisions based on manage-able data. I have been an advocate of sap analysis to evaluate the need for product applications and to evaluate product performance for almost a decade. In that time, many growers have embraced sap analysis and can’t say enough good things about how it has saved them money by reducing fertilizer inputs, how it has made them money by increasing crop yields and quality.

A few growers look at the cost of sap analysis and say, “I can’t afford that.” If you are a small scale market gardner, that may be the case. If you are a professional grower managing a professional enterprise, you can’t afford not to use sap analysis. If you choose not to use it, you chould be clearly aware that those growers who do are rapidly becoming the low cost producers, with the highest profitability.

Mike Omeg from Orchard View shared his experiences with sap analysis on our podcast interview, and I believe you will find them valuable.

Mike: I started the process of focusing on the soil. Many folks have done the same thing, but I started to put on every biological stimulant and inoculant that was available to see what worked. As one would expect, there are some products that work better than others.

What I really learned was that hindsight is indeed 20/20. I found that spraying inoculants onto the bare soil just didn’t make sense, without having material there to protect everything that you’re putting on―to feed everything that you’re putting on. It didn’t make sense. I began to put on material before and after my mulch, because there are some things I wanted to be covered by the mulch and in contact with the soil, and there are other things that I wanted to have on top of the mulch, to add some biological horsepower to the natural processes and to kickstart the natural processes of breaking down that mulch and having it go to work for us in the soil.

One of the things that I began doing was using a lot of fish products. I landed upon a product that I really liked that’s made with salmon and crab. It really pushed forward our soil enhancement efforts, and we saw direct benefit in the crop. We were still a conventionally managed orchard, but we applied this fish product onto the soil and onto the foliage of the trees, and we saw a big return on our investment.

We tried lots of other fish products. As you know, many are available in the market. Some of them work better than others. But the ones we found that were made with salmon and crab here on the West Coast really pushed us forward in our efforts. They’re one of the base components to all my nutrition programs.

John: What other nutritional applications are you using today, and how have they shifted over the last decade or so, since you started experimenting?

Mike: We use nutrition as it’s necessary now. We’re able to do that because we utilize a technique to monitor what’s going on in our orchard in real time throughout the entire season, and that technique is sap analysis.

For many years, in about January or February, I would sit down and I would look at all of the returns that we had for the orchard. I would then look at maybe a couple of leaf samples that we had pulled during the growing season and maybe a soil sample. And I would write down everything I was going to do the following season, and we would follow that recipe. We would make minor tweaks, depending on the size of the crop―if we were going to have a light yield or an average yield or a heavy yield. Maybe we would have a disease problem that started developing, so we would boost a nutrient or two. But we essentially would just follow what was written down on the back of the envelope in the winter. Eight months from when something had been written down, we were doing it.

But an orchard―or any farm―is not a static system. There are all kinds of in-season changes that require us to change our approach in nutrition. But there was no technology that I had confidence in that could tell me what was going on at any moment in my orchard.

Sap analysis changed that. Every two weeks we take a sample―from the time the first leaves are expanded until right before leaf drop. The entire growing season of our orchard, we’re sampling, and we’re sending those samples off and we’re getting the results back and we’re calibrating every nutrient application we put on based on those samples, because we have a real-time picture of what our trees have need for or what they have excess of. Every nutrient in every tank we spray is there because the sap analysis has indicated it needs to be there.

It’s very difficult for me to give generalities about what nutrients we apply. I would love to do that―I’d love to say that our nutrient program is based on X, Y, and Z. But I honestly can only say that fish is something that is in virtually every application. The other nutrients depend upon the results of the sap analysis.

John: How similar are your current types of nutrient applications to what they might have been before you were using sap analysis? Are there still general similarities? Were you applying similar trace minerals? Perhaps a different way of asking the question would be, what were the changes that sap analysis indicated that really surprised you or that were unexpected?

Mike: That’s a great question. I’ll give you some examples.

Before I started doing sap analysis, I would put on semi-loads of triple-20 foliar fertilizer. I would put on large amounts of zinc in the spring, thinking that the trees needed zinc in order to generate bigger leaves, because we all know that bigger leaves on the tree mean more carbohydrates being generated for the tree to size those cherries, and that’s what our goal was.

I’d put on lots of triple-20 and lots of zinc. What I found was that I was shooting myself in the foot because my trees did not need zinc; they did not need triple-20. The potassium I was applying in that triple-20 was pushing calcium out of my trees. When we started doing sap analysis, I found myself putting on oodles and oodles of calcium, and no triple-20, because the trees had become deficient in calcium.

Over time, I was putting on more calcium than I ever could have imagined. And I was putting on no potassium and very little, if any, zinc. That was a big surprise to me, because our baseline program was actually harming our genetic potential of the trees to generate the returns we wanted. I never would have known that I was actually taking away from the potential of the tree unless I had done sap analysis. So that was a big surprise.

I think it was Bill Gates who said something like, “People generally overestimate what they can do in one year and underestimate what they can do in ten.” I love that saying, because as we’ve gone through time, we see things happening in the sap analysis that are surprising.

For example, like I said, we applied lots and lots of calcium when we first started this process years ago. What we see now is actually that our calcium levels are quite good. I never thought I would have said that, given how much calcium we put on. But through the various activities we’ve been doing―focusing on our soil and our foliar nutrition, based on sap analysis―we’ve gotten our calcium levels up to where I’m comfortable with them.

Believe it or not―I never thought I would say this in a million years―we actually had a difficult time keeping our nitrogen levels up in the last growing season. I found myself actually putting on a large amount of nitrogen, relative to what we’d done in the past, because our nitrogen levels weren’t high. We needed them to be higher. That was a big surprise.

I never would have done the right thing and put on nitrogen, and backed off on our calcium applications, had I not had sap analysis right there in front of me, showing me the trends in those two nutrients and allowing me to take action to correct them.

John: We’ve certainly observed that adopting sap analysis is one of the hallmarks of really exceptional growers. Because if you’re not testing, and if you’re not measuring, then you’re just guessing. There are many growers who have historically been comfortable with guessing, and that’s rapidly shifting and changing.

Mike: It sure is. There are probably growers out there who are so in-tune with their crop that they might be able to look and be lucky. Then they tell themselves that they’re never wrong. And boy, that’s a mistake.

I think that sap analysis has been foundational in allowing me to efficiently use the biologically intensive techniques I’ve been using on my farm and to have a return on investment. I don’t sell my fruit direct-to-consumer―I sell my fruit into the wholesale market. I don’t have the luxury of my own brand―my face on the package, so to speak. My fruit is anonymous in the marketplace. The only thing that my fruit has to speak for itself in the marketplace is the size and quality of the fruit.

Because of that competitiveness in the market, I have to make sure I am very efficiently managing my inputs, because I don’t receive a brand premium. I get a premium price because my quality is above average, generally. Nobody’s perfect, and it’s not always that way, but the quality of my fruit is above average. And it needs to be if I want to compete in the wholesale market.

The use of bio-intensive practices has to be done in a way that ensures a return on investment, because these expenses are added expenses versus the conventional fruit that I’m competing against in the marketplace. They often require higher levels of management and labor―which, of course, are two of the more expensive things for a business.

But by doing sap analysis, I am able to make sure that I’m hitting the mark with these techniques to the best of my ability. That adds a very important boost to the return on investment, because we’re targeting them perfectly. The efficacy of that investment becomes quite high when, instead of just guessing with something that’s an expensive input, you’re putting an expensive input right where it needs to be at the right time, in the right amount. The return on investment is quite substantial when you start doing that.

You can learn more about sap analysis from Crop Health Labs.

2020-06-23T13:03:13-05:00June 30th, 2020|Tags: , |

When micronutrient levels in tissue analysis don’t correlate with field observation

My frustration with tissue analysis a decade ago that lead to our use of sap analysis was that tissue analysis results did not correlate to disease and insect pressure, which the literature indicated should be possible. Tissue analysis also did not correlate with field observation of deficiency symptoms. Michael McNeill discusses how accumulated pesticides residues in the soil profile can chelate micronutrients, and continue to hold them in chelated form even after they have been absorbed by the plant. The chelation constants of many pesticides are much stronger than naturally occuring chelation agents like amino acids and organic acids.

From the Regenerative Agriculture Podcast with Michael McNeill:

John: Michael, what is something that you’ve puzzled over for a really long time? What’s really caught your attention in the agriculture space that you’ve been working on?

Michael: Well, something that I’ve finally figured out, I think, was the impact of the lack of availability of micronutrients in our crops. I was doing tissue testing, for example, and I had adequate copper and iron and manganese and magnesium and calcium—everything looked good. What I didn’t realize was that a lot of those minerals were chelated. They were tied up into a form that the plant could not use—yet they showed up on a chemistry test when we tested the tissue. And when I finally figured that out, then everything started to gel for me.

John: I think what you’re saying is that these various minerals and trace minerals were being chelated inside the plant tissue by the herbicides and fungicides that growers were applying.

Michael: Yes. When I tested the plant, it had adequate levels. But when I looked at the plant, it was showing deficiency symptoms. You could look at it and just tell that there was a zinc deficiency or a manganese deficiency; it was obvious. But when I tested it, it was fine. Why was that? And it’s when I learned about this chelation issue and how it can be such a problem.

John: This is something we’ve been monitoring for a number of years. And it seems that, in some cases, sap analysis reports those a bit more accurately. And perhaps that doesn’t take all the chelation into account—but of course it’s still extracting nutrients that are held within the plant sap, and it’s still possible for them to be chelated. We do see the sap analysis correlate more accurately to what the plants are actually showing visually.

Michael: I would agree. I think the sap analysis has been a good step forward. When I figured out this chelation effect, that’s when it really gelled for me and I could understand why I was seeing deficiency symptoms in what, on paper, looked to be an appropriately healthy plant.

Why we don’t use Horiba meters to measure nutrients in plant sap

Laboratory leaf sap analysis has given us remarkable insights into plant nutrition. We have learned a great deal about nutrient interactions and plant nutrient absorption of different products and in different environments, and have become champions of sap analysis. 

Occasionally I am asked how we might use the Horiba meters to measure sap contained nutrients in the field, rather than submitting them to a lab.  

I don’t consider Horiba meters to be a viable option if we really want to manage plant nutrition properly. Here are a few reasons why: 

  1. We need to know the levels of many more than four or five nutrients. Knowing the levels of only nitrate, potassium, calcium, sodium, pH, EC, and Brix doesn’t begin to approach the thoroughness of data needed to make informed decisions about nutrient management. For example, manganese influences potassium absorption, and boron influences calcium absorption, to a significant degree. Trying to manage the macronutrients without knowing the levels of the trace minerals promises to be an exercise in frustration and mismanagement.
  2. Nitrate is only one of many possible forms of nitrogen contained within a plant. In a healthy plant with proper protein synthesis, upwards of 80% of the nitrogen will be in the form of enzymes – complete proteins, which don’t register at all on a nitrate meter. It is possible to have a crop with abundant levels of total nitrogen and record a non-detect nitrate on a Horiba nitrate meter. With lab-based sap analysis, nitrate, ammonium, and total nitrogen are all measured separately. Our goal is to have abundant total N, with nondetectable levels of ammonium and nitrate. A goal that we achieve quite regularly.
  3. In many cases, (not always) in-field analysis with the Horiba meters is conducted on the sap contained within the petiole, rather than in the leaf. Yet, we know the petiole is a nutrient and water transport pipeline, and nutrient levels in the petiole sap can fluctuate by as much as 30-40% at different periods during each 24-hour photocycle. With what other analytical methods would we accept a possible 30+% error margin? None, of course. We can reduce this margin of error by collecting samples at the same period of each day, but this doesn’t resolve the challenge that the nutrients contained within the petiole don’t always reflect what is present in the leaf.

In –  lab analysis of leaf sap overcomes all of these challenges. This is why we only use the sap analysis from Crop Health Labs.


2020-03-16T13:52:03-05:00January 10th, 2020|Tags: , |

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