GlueSniffer
Active Member
“How to Design Foliar Sprays” (YouTube video from May 14, 2019)
Advancing Eco Agriculture
John Kempf
(Warning that is is just a summary based off notes I took while watching the 45 minute video. Please watch for yourself for the full, unadulterated version. Don't blame me for anything that you disagree with, but please correct me if my summary doesn't correspond with the video. I'm just trying to share information that some may find helpful. Feel free to discuss and ask questions, but I probably don't have any answers. Again, I am not the source of this info. There is also a related video "Foliar Feed Tips" by Soil Doctor Bryant Mason. It is only 5 minutes and more to the point. It has a few other tips included not in the Kempf video.)
Synergistic Stacking
Nutrients, when combined with plant and microbial biostimulants plus microbial inoculants are more effective than using any single product alone. Well-designed, stacked foliar spray solutions should include all of these.
Kempf often says “One plus one equals eleven.” - I don't think he mentions this in this video but it applies so I added it here.
For example, if wanting to feed seaweed, magnesium, and manganese - stack them together in one spray solution. Combining all three will give better results and any one or two alone. Seaweed will work best if nutritional needs are already met.
A well designed foliar feeding might also increase the absorption of nutrients that were not included in the solution. For example, you might see zinc, copper, and boron absorption rates increase even though they were not applied in that particular foliar.
What to Include in Every Well Designed Foliar Spray
Mixing Sequence
Favorable Foliar Spray Solution Characteristics
Materials such as magnesium chloride, potassium nitrate, calcium chloride, and calcium nitrate all have high points of deliquescence. Adding small amounts of these to a foliar spray solution will help keep the foliar application in liquid form on the leaf surface for a longer period of time (even in low humidity). These materials will pull water out of the air so droplets on a leaf surface will remain liquid for longer periods of time.
A foliar spray solution with a high point of deliquescence should vastly increase the intake of the nutrients and effectiveness of the application. Staying in liquid form for longer periods of time will give microbial populations on the leaf surface a longer time to digest the nutrients and give more time for the nutrients to be absorbed through the leaf surface (via the stomata, diffusion through cell membranes…)
What is Clean Water?
Clean water is rare. For purposes of foliar applications, it is water with less than 70ppm total hardness (less than 5 grains). Hard water is created from Calcium and Magnesium - Carbonates and Bicarbonates. The most common challenge comes from Calcium Bicarbonates. Bicarbonates and Carbonates are two very reactive anions that love to bond with anything that will be added to a spray solution.
If water has 150 ppm of total hardness (10 grains) products will be up to 70% less effective because the carbonates and bicarbonates are so effective at binding with these products. This applies to fertilizers, biostimulants, inoculants, pesticides, insecticides, herbicides, and fungicides… Any product.
The use of RO water (compared to using a hard water source) can reduce product application rates by 30-50%.
Clean Water Sources
-Rain Water
-RO Water
-Tested Clean Water
What about other Water Sources?
-Softened water will have too much Na or Cl. It shows up in plant testing.
-Filtered water will often still have the carbonates and bicarbonates.
-Pond or stream water will need testing because the water can pick up bicarbonates from rocks as it travels. Snowmelt is usually fine.
-City water has antimicrobials. (chlorine, chloramines...) Plus my city water tested for 125 ppm of bicarbonates.
-Chemically acidified water
(using phosphoric acid, sulfuric acid…to neutralize carbonates and bicarbonates and lower pH)
Acidifying your hard water WILL help some (compared to doing nothing), but is usually not effective enough.
If lowering pH into the desired range (5.2 to 6.4), these acids will not completely neutralize the carbonates and bicarbonates in hard water.
Timing of Application
Best in Evening or Early Morning
When NOT to Apply
-When leaf surface temperatures are above 78 degrees F
-During rainfall
-While there is heavy dew
Why to Foliar Feed?
Healthy plants make healthy soil. Foliar feeding can increase plant health which in turn can increase soil health. Healthy plants have roots that exude more carbon into the soil which provides the organic matter that acts as the substrate for the microbial activity. Plants create healthy soil, not the other way around.
Brix As Measurement of Effectiveness
Foliar applications can improve plant health and increase Brix numbers over time. Brix will spike after an effective foliar spray. Within 30 minutes to 24 hours, there should be a spike in measured Brix. If not, the spray might not be effective. Following the initial spike, Brix will gradually reduce back down to a baseline over time. If the system is healthy, the gradual decrease of Brix might last 4-6 weeks after the application. If the system is stressed and unhealthy, the Brix will fall all the way back to the baseline more rapidly (as quickly as 3 days).
As the system becomes healthier (up to a point), subsequent foliar applications become more effective. There will be a bigger spike in Brix, the Brix will remain elevated for a longer period of time, and the Brix baseline will continue to increase with each application as plant and soil health continue to improve. Smaller quantities of products will be required to get maximum benefits as the health of the system improves. Best responses come when plants are very stressed. As the plants become healthier (next level type health), the 'response to' and 'need for' foliar applications will decrease.
Once the baseline Brix is high enough, the plant will not need additional inputs to sustain that level. The plant will be resistant to diseases and insects. The whole plant needs this high of a Brix level. Leaves, stems, fruits… If any part of the plant has low Brix, the weakest part of the plant (often fruit for reproductive crops) will still be susceptible to disease and insects. After getting plants to this level of health, the plant / soil / microbe system can become self-sustaining.
If you found this informative or helpful let me know. Next I want to take notes on "Managing Nutrition at Critical Points of Influence"
Advancing Eco Agriculture
John Kempf
(Warning that is is just a summary based off notes I took while watching the 45 minute video. Please watch for yourself for the full, unadulterated version. Don't blame me for anything that you disagree with, but please correct me if my summary doesn't correspond with the video. I'm just trying to share information that some may find helpful. Feel free to discuss and ask questions, but I probably don't have any answers. Again, I am not the source of this info. There is also a related video "Foliar Feed Tips" by Soil Doctor Bryant Mason. It is only 5 minutes and more to the point. It has a few other tips included not in the Kempf video.)
Synergistic Stacking
Nutrients, when combined with plant and microbial biostimulants plus microbial inoculants are more effective than using any single product alone. Well-designed, stacked foliar spray solutions should include all of these.
Kempf often says “One plus one equals eleven.” - I don't think he mentions this in this video but it applies so I added it here.
For example, if wanting to feed seaweed, magnesium, and manganese - stack them together in one spray solution. Combining all three will give better results and any one or two alone. Seaweed will work best if nutritional needs are already met.
A well designed foliar feeding might also increase the absorption of nutrients that were not included in the solution. For example, you might see zinc, copper, and boron absorption rates increase even though they were not applied in that particular foliar.
What to Include in Every Well Designed Foliar Spray
- Clean Water
- Plant Nutrients / Fertilizers
- Plant Biostimulants (seaweed, hormones, enzymes…)
- Microbial Biostimulants (fulvic acids, humic substances…)
- Microbial Inoculants
- Surfactant
- *Material with High Point of Deliquescence
Mixing Sequence
- Fill Tank with Clean Water
- Pesticides (want these diluted before adding stimulants and inoculants)
- Fertilizers / Nutrients
- Plant Biostimulants
- Microbial Biostimulants
- Microbial Inoculants
- Surfactant (want to add this last)
Favorable Foliar Spray Solution Characteristics
- pH of 5.2 to 6.4
- Electrical Conductivity of less than 3800 (or 3.8 on different scale) if applying every 10-14 days. If applying every 30-40 days EC range is not as much of a concern. (NOTE: Soil_Doctor says use EC of 1.5 (1500) to 2.5 (2500) if using biologicals. Up to 4.0 EC if not using biologicals. On my EC meter, 750ppm = 1500 (1.5) EC, 1250ppm = 2500 (2.5) EC, 2000ppm = 4000 (4.0) EC.)
- High Point of Deliquescence (This describes the humidity tipping point where a water droplet can either remain liquid or will dry-out if humidity is reduced past this threshold.
Materials such as magnesium chloride, potassium nitrate, calcium chloride, and calcium nitrate all have high points of deliquescence. Adding small amounts of these to a foliar spray solution will help keep the foliar application in liquid form on the leaf surface for a longer period of time (even in low humidity). These materials will pull water out of the air so droplets on a leaf surface will remain liquid for longer periods of time.
A foliar spray solution with a high point of deliquescence should vastly increase the intake of the nutrients and effectiveness of the application. Staying in liquid form for longer periods of time will give microbial populations on the leaf surface a longer time to digest the nutrients and give more time for the nutrients to be absorbed through the leaf surface (via the stomata, diffusion through cell membranes…)
What is Clean Water?
Clean water is rare. For purposes of foliar applications, it is water with less than 70ppm total hardness (less than 5 grains). Hard water is created from Calcium and Magnesium - Carbonates and Bicarbonates. The most common challenge comes from Calcium Bicarbonates. Bicarbonates and Carbonates are two very reactive anions that love to bond with anything that will be added to a spray solution.
If water has 150 ppm of total hardness (10 grains) products will be up to 70% less effective because the carbonates and bicarbonates are so effective at binding with these products. This applies to fertilizers, biostimulants, inoculants, pesticides, insecticides, herbicides, and fungicides… Any product.
The use of RO water (compared to using a hard water source) can reduce product application rates by 30-50%.
Clean Water Sources
-Rain Water
-RO Water
-Tested Clean Water
What about other Water Sources?
-Softened water will have too much Na or Cl. It shows up in plant testing.
-Filtered water will often still have the carbonates and bicarbonates.
-Pond or stream water will need testing because the water can pick up bicarbonates from rocks as it travels. Snowmelt is usually fine.
-City water has antimicrobials. (chlorine, chloramines...) Plus my city water tested for 125 ppm of bicarbonates.
-Chemically acidified water
(using phosphoric acid, sulfuric acid…to neutralize carbonates and bicarbonates and lower pH)
Acidifying your hard water WILL help some (compared to doing nothing), but is usually not effective enough.
If lowering pH into the desired range (5.2 to 6.4), these acids will not completely neutralize the carbonates and bicarbonates in hard water.
Timing of Application
Best in Evening or Early Morning
When NOT to Apply
-When leaf surface temperatures are above 78 degrees F
-During rainfall
-While there is heavy dew
Why to Foliar Feed?
Healthy plants make healthy soil. Foliar feeding can increase plant health which in turn can increase soil health. Healthy plants have roots that exude more carbon into the soil which provides the organic matter that acts as the substrate for the microbial activity. Plants create healthy soil, not the other way around.
Brix As Measurement of Effectiveness
Foliar applications can improve plant health and increase Brix numbers over time. Brix will spike after an effective foliar spray. Within 30 minutes to 24 hours, there should be a spike in measured Brix. If not, the spray might not be effective. Following the initial spike, Brix will gradually reduce back down to a baseline over time. If the system is healthy, the gradual decrease of Brix might last 4-6 weeks after the application. If the system is stressed and unhealthy, the Brix will fall all the way back to the baseline more rapidly (as quickly as 3 days).
As the system becomes healthier (up to a point), subsequent foliar applications become more effective. There will be a bigger spike in Brix, the Brix will remain elevated for a longer period of time, and the Brix baseline will continue to increase with each application as plant and soil health continue to improve. Smaller quantities of products will be required to get maximum benefits as the health of the system improves. Best responses come when plants are very stressed. As the plants become healthier (next level type health), the 'response to' and 'need for' foliar applications will decrease.
Once the baseline Brix is high enough, the plant will not need additional inputs to sustain that level. The plant will be resistant to diseases and insects. The whole plant needs this high of a Brix level. Leaves, stems, fruits… If any part of the plant has low Brix, the weakest part of the plant (often fruit for reproductive crops) will still be susceptible to disease and insects. After getting plants to this level of health, the plant / soil / microbe system can become self-sustaining.
If you found this informative or helpful let me know. Next I want to take notes on "Managing Nutrition at Critical Points of Influence"
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