Let's ask a hydrogeologist! I recently had the opportunity to sit down with Timothy Parker of Parker Groundwater Consulting in Sacramento, CA.  Timothy Parker began his career as a regulator working in contaminant hydrogeology. He got involved with fresh water while working for the California Geological Survey, doing watershed assessment and timber harvest oversight, and for Department of Water Resources, providing assistance to local agencies on groundwater and conjunctive management projects. He also worked in the oil industry applying advanced oilfield technologies to groundwater ma ..read more

Rebuilding habitats for natural rodent control The following article was originally posted in Wine Business Monthly in April of 2022.  Did you know that owls are cannibalistic? Baby owls will feast on their owlet-siblings to reduce competition. Did you know that owls strike so fast they kill on contact? It’s the equivalent of getting hit with a truck…a truck with talons. I love talking to bird people. They’re such sadists. Or rather, they look at the grim brutality of the natural world and dive right in. They’re the ones who root for the T-Rex in Jurassic Park. In Don’t Look Up, they’r ..read more

A couple weeks ago I was asked by Tim Carl over at Napa Valley Features to write a review of the 2023 season with a focus specifically on Napa. Check out the original post here and be sure to browse the rest of this remarkable publication. 2023 has been a weird one. While the rest of the nation got a taste of what hellish future awaits our grandchildren, here in California we enjoyed a cool spring followed by a temperate summer. In many areas this equated to prime growing conditions for high-quality grapes. In other areas, it didn’t. I wrote about California more generally here, but I wanted t ..read more

Yesterday marked the official end of the growing season and what a season it was, amiright?? 2023 has proven to be polarizing. For some growers and winemakers, this was a remarkable year for quality, and others are just thankful to have crop insurance. Let’s take a look at why this is. I wrote about how 2023 was shaping up back in July when I looked at how Growing Degree Days (GDD) were stacking up compared to other years. GDDs are typically calculated by taking the average of the daily minimum and maximum temperature and subtracting a base number, in this case 10°C (50°F). Back in July, mos ..read more

Let’s look at some data. I once saw a commercial that said: “forget everything you thought you knew about slip covers”. So I did. Admittedly I don’t know a lot about slip covers. I do know quite a bit about plant stress. Up until recently, our constant flow of data on soil moisture has been studied along with weekly spot measurements of leaf water potential via pressure bomb. This year we switched to FloraPulse® plant stress sensors and holy moly, having real time data on plant stress is pretty wild. First of all, how much data are we talking about?   This graph compares our real tim ..read more

No, we aren’t breaking up. This year has been a little weird. We got a lot of rain and up until recently it’s been markedly cold. How different is it though? One thing I like to keep in mind is that the last few years have been hot and early. Perhaps this is just a normal year and we’ve forgotten what normal looks like. Although there’s been some argument about its importance, the Winkler Growing Degree Day formula allows us to compare different seasons using the same metric. Growing Degree Days (GDD) are calculated by subtracting the grapevines’ threshold temperature (50°F) from the daily ..read more

When it comes to micronutrients, good things come in small quantities By Mark Greenspan  The following article first appeared in Wine Business Monthly in June, 2014. Read the original article here.  When it comes to vine nutrition, most of us think about the N-P-K we’re putting out. That makes sense, because each and every year we remove many pounds of these nutrients (mostly N and K) from our vineyards by removing crop and shipping it off-site. Replacement of these macronutrients (N, P, K, Ca, Mg) is usually applied through application of granular fertilizers, liquid fertilizers ..read more

How can I find out? Despite the deluge we Californians got this winter and early spring, we’re not out of the drought. Many of the state’s groundwater basins are still overdrafted, some by a lot. The reason we’re in dire straits right now is because of agriculture. There are not enough low-flow toilets in the world to offset the water requirements of the Central Valley. Most of that demand is irrigation-related and that seems to be the focus of water-savings measures. I know we at AV certainly hang our hat on it. But there’s an elephant in the room… Its name is frost protection. Now frost ..read more

After the flood…Part deux! How did the recent rains affect your aquifer…if at all? California was hit by some torrential rain in January. In our last post, we explored how that rain had affected soil moisture. In some cases, the water percolated right through and left the soil dry again. In other cases, the rain filled the soil to field capacity. It all depends on the soil’s water holding capacity. The rain we get now probably won’t have much of an effect on the coming season. By the time we get shoots pushing, even heavier soils will most likely need some water. That is assuming we don’t ..read more

Looking like a great year (for trunk disease) Sorry to be a Negative Nancy... The recent rain we’ve been getting is certainly a welcome change for us in California. Wet weather does, however, present other challenges especially going into the pruning season. That’s right. I’m talking about trunk disease. It’s everywhere, and like viruses, growers like to pretend they don’t have it. After all, it takes years before symptoms express themselves and even longer before they amount to an economic loss. But economic loss from trunk disease is real and, uh, expensive. No one likes being told thei ..read more