Welcome to the Ultra Gro Agronomy Letter!
In this letter we have a visit with JJ Magdaleno who helped assemble the Terra Nova Trading Crop Estimate (click here to view). And as a follow up to JJ’s observations of the almond crop suffering from water/heat stress, we asked Robert Smith and Rich Kreps to give us some ideas for all of us to use that might stretch our water use
The TNT Crop Estimate and JJ Magdaleno
Last week, Terra Nova Trading issued their 2022 Crop Estimate (2.9B/2,100 lbs per acre). As we all know, this is a widely followed, sometimes-controversial and always talked-about report that has a relatively high level of accuracy (+/-97%) over the years.  

This year’s report addressed many of the issues surrounding the almond crop, ranging from February frost damage to drought affected orchards…it was hard to find any good news. We spoke with JJ Magdaleno (one of the contributors to the report) for some color. Here’s what we heard…

Frost Damage
Q. Can you try to put a number of the frost damage?
A. “You can’t count what you can’t see…all we know is there are several orchards out there that were devastated, especially in Sac Valley and in parts of Stanislaus and Fresno Counties. Worse than 2018. We account for it in our estimate."

Last year, as a general statement, the crop came in a little below many estimates (2.8B vs +/-3.0B). Many reasons have been put forth to explain a slightly shorter crop, including; sizing issues, crop loss due to deficit irrigation, crop loss due to outright heat stress, small set due to declining tree health, etc…virtually all of these problems are water/weather related. The TNT report really brings out the difference between farmers that have water and those that do not… “the haves and the have-nots”. We asked JJ about this…

  • Tree health- Last year at this time, tree health seemed to be considerably better than what we have seen this year…there are just more stressed-out orchards coming into the year, of course all in poor water areas.

  • Sizes- Were a big problem last year…we think deficit irrigation played a big role in that, as well as extreme heat in the summer.

  • Weather- Last year the crop degraded from this point forward, especially in water stressed areas, due to a very hot summer. As mentioned above, this also played a role in sizing…can’t control the weather…hopefully this summer is less severe.

  • New Plantings- Farmers that have water seem to be re-planting orchards, farmers that don’t have water, have not. Given the economics found in today’s market, we were surprised at how many new plantings we found, although a vast majority of new plantings seem to be found in the central and east side of the state.

  • Abandonment – With the price of almonds, cost increases of inputs, limited access to water, and increasing removal costs, we are seeing a lot more abandoned orchards, again mainly in the south and west side.  

Deficit Irrigating Tips
by Robert Smith, Agronomist
In the San Joaquin Valley, we have approached the point that growers and their irrigation managers are planning deficit irrigation strategies around hull split. If you have not thought this through, it would be very beneficial to spend some time to plan your irrigation before it is a crisis. 
This water use is driven by the process of gas exchange of carbon dioxide and transpiration which is required for photosynthesis. Environmental conditions (hot and dry will use more than cool and humid), the percent of the ground covered by the plant (higher percent, more water use, but more yield), and the stage of the plant (large leaves use more than little leaves) impact the amount of water required per acre/plant.

In years where less water is available, deficit irrigation can be used with little negative effect on yield if it’s carefully monitored. A well-planned plant-driven nutrition plan and managing plant stress during peak heat/drought stress is essential. Since a drought situation is not “business as usual,” there is a need for a carefully planned strategy on how best to utilize the water that is available. This practice, however, can have negative impacts when applied incorrectly. During deficit irrigation, irrigation can be reduced until soil moisture levels deplete below 50%.

For almonds, this strategy is most commonly used around hull split.

General guidelines on the timing and duration of almond deficit irrigation:
1. When a “V” begins to form on the hull just prior to the start of hull split, irrigations should begin to decrease. During this time, if your soil moisture levels are already depleted, it’s important not to induce any more stress than what is already there.
2. The period of deficit irrigation should last no longer than two weeks to prevent any long-term damage. Inducing too much stress for too long is detrimental to your crop as this final phase in development is occurring in preparation for harvest. When your two weeks of deficit irrigation are finished, resume your irrigation schedule and begin to fill the soil profile again just before harvest. 

For pistachios, deficit irrigation is best used during shell hardening (phase 2) and post-harvest.

General guidelines on the timing and duration of pistachio deficit irrigation:
1. For pistachios the critical periods when you cannot under-irrigate are from bloom to shell expansion (stage 1) and nut filling to hull slip (phase 3).
2. Studies have shown that the best production occurred with deficit irrigation during Stage 2 at 50% of near-potential ETc during Stage 2 and 25% of near-potential ETc after harvest.

If possible, schedule your irrigation during early morning or late evening (between 7pm and 7am) to avoid evaporation losses. Temperatures are higher during the day, and this can lead to excessive water losses, thus reducing the overall efficiency of the irrigation system. However, scheduling irrigation during early morning or late evening may not be practicable for some production systems due to crop type, system design, and logistics of operation.

California’s climate is normally hot and dry during the summer months, but drought conditions and higher-than-average temperatures make farming even more challenging. The establishment of these strategies can be used to ensure that your farm remains productive during drought.
We know these are some general guidelines and everyone has a different set of problems. Please feel free to call me or your Ultra Gro Crop Advisor for more details, or, with any help I can lend to your specific situation. I can be reached at my cell phone: 559-907-8405.
Oxygen in the Root Zone and Pulse Irrigation
by Rich Kreps, CCA and Ultra Gro Partner
We spend so much time talking about getting 17 nutrients right, we often forget about the three most abundant nutrients; hydrogen, oxygen and carbon. Getting your water right takes care of two of those in hydrogen and oxygen, while the air our plants breath handles carbon and oxygen. Oxygen is pretty important. And keeping some in our root zone is also equally important. Those long sets trying to push deep moisture past 3 feet may be critical before harvest when water stress reaches a maximum, but it may not be as critical as we used to think in-season and especially in spring and early summer. 

Applying the principles of pulse irrigations may be our answer when we face the mountain of restrictions SIGMA and a lack of surface water will impose. It has been our experience that our growers who have been applying shorter sets of water more often are seeing less stress in their fields, less subbing up of deep moisture and better nutrient absorption. There are countless studies that show how important it is to have an active soil to increase your crops nutrient uptake. In the face of doubling Nitrogen prices and the entire gamut of nutritive to price increases, getting more of what you apply into your crops is the target we should be shooting for.
Using shorter sets, allowing our soils to create pore space and more oxygen in the root zone more quickly after irrigations has been beneficial to creating a soil environment conducive to increasing biological diversity and sustainability. Longer sets tend to create more anaerobic conditions for a longer period of time in our soil. This not only increases the bad bugs, but decreases those beneficial bacteria, fungi and yeasts our crops rely on to assimilate nutrients. 

As a practical example, changing our irrigation sets from (1) 48-hour set to (3) 12-hour sets per week may not only save us several inches of water in a season, but allow us to keep more nutrition in our root zone. Lowering our inputs both in water and nutrients may just be the ticket to being profitable in the current environment, yet still keep our crops healthy and our yields up. 
I am always available, feel free to call me if you need any additional information. My cell phone number is: 559-706-6903.