By: Orest Protch
The Impact of Water Irrigation is more then turning on your Sprinkler or Drop Irrigation. Although the water you see may look, well, boring, when you delve deeper into its secrets, you are entering the realm of rocket science, with a dash of magic and a pinch of voodoo.
Vineyard water chemistry is more than just pH and a few other high school level chemistry tests. It can possibly explain why some vineyard wines can be award winning some years and other years be best forgotten.
Vineyards take their raw water from lakes, rivers, water wells and in some cases use treated potable municipal waters. No two waters carry the same chemical and nutrient loading. And this loading taken from the same source can even vary daily, monthly and yearly.
One side of a lake may have different water chemistries than the other due to the way water flows through it. It can have numerous streams and rivers feeding it, each draining a different watershed. These may be draining mineral outcroppings, storm sewers, municipal wastewater plant discharges, mines, farms and even burnt forests. Each of these will add differing kinds and amounts of chemical elements and compounds to waters. Even a few hundred meters apart, water samples will show varying amounts of TDS, total dissolved solids and TSS, total suspended solids. One stream may discharge its nutrient load farther into a lake than another.
As an exercise, If your vineyard is on a lake or river, download a satellite image and mark its location in relation to all of the above. You may be shocked at what you see.
At one point in my career as a research chemist in a pulp mill first owned by Proctor & Gamble and then by Weyerhaeuser, I believed that the seasonally changing chemistry of incoming river water for the mill was impacting the final pulp fiber morphologies in different ways throughout the year. The mill pumped in 6.3 million litres per hour, 24 hours a day.
I proved that individual elements such as iron, calcium and sodium in the river water, in parts per million (ppm) and parts per billion (ppb), were impacting the final processed fiber properties by interfering at the chemical bonding sites of the fibres at the molecular (atomic) level. 15 pulp mills in both corporations changed the way they ran their processes.
I then carried this type of testing later in my final career as a senior lab technologist for an oil company using an ICP-OES, (Inductively coupled plasma optical emission spectrometer). The flame of this instrument burns at a temperature 2,000°F hotter than the surface of the sun. I measured elements down to the very low ppb level and high ppt levels in daily/weekly process and environmental samples from lake water, river water, fresh water wells and brackish water wells. Even in the harsh industrial environment of oil production, as in the pulp mill, the changing water chemistries manifested their effects.
Plant roots absorb the waters and simple elements such as iron and cobalt and along with plant enzymes and biological catalysts, create the complex chemicals in grapes. Throughout the complicated grape’s biological chemical processes, water chemistry changes can inadvertently modify chemical reactions and the final reaction product can change.
What happens in a vine is the equivalent to the most complicated industrial chemical processes known.
During all chemical reactions, elements and chemical compounds look for reaction bonding sites and at the molecular level zero in on specific locations of individual molecules of plant cells. Plant cells absorb these and start creating sugars, acids, phenolics, ethonals, enzymes, montoterpenes and a host of other products that give the mature grape its final properties. But as in all complex chemical reactions, simplicity does not exist. Different atoms, due to their concentrations, may battle it out for molecular bonding sites.
Elemental bonding sites are the drivers of all reactions. Some chemical bonds prefer other elements if they are available and so the final molecule may not be the one a vineyard wants in a grape. It all comes down to concentrations and availability of needed as well as competing atoms.
Figure 1 is part of an actual 2019 Government lake water analysis report for the local vineyard industry. If this report had been generated by a third party commercial laboratory for me at my previous work position, I would have rejected it. Look at the number of decimal places and zeros of elements such as cobalt and iron. Research papers show all the elements in the figure are important for grape development. This analysis was obviously done on a very basic ICP, Inductively Coupled Plasma Spectrometer, found in all commercial labs.
Figure 2 is the type of analysis that an instrument like the ICP-OES that I used can give. It can reach detection levels by a factor of 100 to 1,000 lower than a basic ICP. In this case the difference between the detection limit of 5 decimal places in cadmium and chromium with 6 decimal places was the quality of the standards used to calibrate the instrument on a daily basis. Analytical standards can vary batch to batch.
Why is it important for vineyards to have the most accurate and precise analysis of their waters? Just like in metallurgy and metal standards, trace amounts of elements can have large impacts on chemical and physical characteristics.
The analysis report in Figure 1 lists iron composition at <0.010 mg/L. This is completely useless information for a vineyard and a waste of test analysis money.
What if the mg/L of iron required to make a grape that creates that reproducible excellent wine that you are striving for is between 0.0012 mg/L and 0.0079 mg/L and anything out of that range changes your grape’s characteristics? This kind of tight elemental tolerance is the most critical aspect of a metal’s metallurgical grade. Why would the extremely complicated chemical composition of a grape be any different?
The best instrument for extreme lower detection limits is an ICP-MS, Inductively Coupled Plasma Mass Spectrometer. It can not only easily go to the very low ppb, but to the very low parts per trillion range. A basic ICP will cost about $75,000, (all these costs in CDN$) an ICP-OES $140,000, an ICP-DRC (Inductively Coupled Plasma Dynamic Reaction Cell) $200,000 and an ICP-MS upwards of $500,000. All contract labs will have an ICP, some will have an ICP-OES and perhaps a few an ICP-DRC and only a very few will have an ICP-MS. For any given sample, the analysis cost reflects the cost of the instrument and the professional level of the analyst. For example, an ICP water analysis may cost $100, an ICP-OES analysis $150, ICP-DRC $200 and using and ICP-MS $300.
These are all just examples and the actual costs will be determined by working with your contract lab’s client account manager. If asking for XRD analysis for leaf and soil analyis, there is only one lab that I know of in Canada where the analysts are all PhD’s. I only used that lab. You get what you pay for.
Remember, this is a long term endeavor, much like your goals to create great award winning wines year to year.
Your winery, land and associated equipment are worth many millions. The quality of your wines and your reputation is priceless. Do all that you can to win awards every year. In the next article we can discuss the rocket science of soil chemistry. Cheers!