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Why Soil pH is Out of Your Hands

An introduction to soil pH

Soil pH in a landscaping setting is often misunderstood by landscapers, gardeners, arborists, and novices alike. This could be due to the limited availability of science-based landscaping information. Most relevant information comes in as recycled science from the farming industry where more money is available for scientific research. The lack of money invested in the study of landscape science forces a connection between the farming and landscaping industries. And much like the situation in Cinderella with all those people trying to fit her show…it’s not gonna work!

The most important piece of information that often gets lost in translation is that established plants produce and adjust their own pH levels regardless of parent soil pH. Because farmers grow different crops on the same fields and these are annuals, soil pH actually matters. This is because the crops won’t be in the soil long enough to effect change before they are switched out for new crops requiring a different pH level. If any one of these crops stayed for an extended period of time, they would need to adjust their own pH levels. In short, plants do not need soil pH adjusted for optimum growth. Measured readings of pH levels are not necessarily accurate to what the plant creates for itself. This can mislead the gardener, landscaper, or arborist thinking that the pH is off when in fact, according to the plant, the pH is perfect.

Is soil pH an exact science?

Soil science relating to pH levels is typically an exact science except for where it pertains to plants in an established landscape setting. This includes gardens and established wooded areas. While measuring soil pH is one thing, being able to change pH levels on a more or less permanent basis to an established planting of any kind without causing physiological damage to the plant is another. In any case, the soil buffering capacity will prevent any long-lasting change to pH levels, but your plant will forever be changed by the treatment.

The problem occurs when science tries to group soil technology, farming, and landscaping into one box. Nearly everything science has to offer a gardener, landscaper, or arborist comes from studies done to the farming industry even though these two are only slightly related. The biggest difference is that farmers rarely deal with established plants. Farmers will measure the field pH levels to determine what is needed for their crops to be grown and the soil pH is successfully adjusted. It is impossible to change the pH of the soil where the existing plant has influence over the pH levels without causing physiological damages to the plant.

Where is soil pH most important?

The soil-root interface is where the pH is the most important; however, this is also where it is hardest to measure. The average gardener cannot measure pH at the soil-root interface. The pH changes with the order magnitude as you move away from the soil-root interface, so the soil you measure for pH does not in fact represent the pH at the soil-root interface. This means that the pH readings you get will be largely inaccurate, thus leading you to false conclusions about the condition of your plant.

The interface between the soil and the root.

At the soil-root interface, the proton pumps exude and absorb hydrogen. This area is very sensitive to disruptions and disorders. Some of these disruptions can include artificially changing the pH levels in the soil, soil compaction, herbicide injury, alcohol poisoning from anaerobic conditions caused by standing water, and more.

Where does hydrogen in plants come from?

All hydrogen that originates in plants comes from water. That’s why plants “breathe” out oxygen. The oxygen produced by plants comes from what is left after the hydrogen is pulled from the water. The hydrogen then makes its way through the plant headed toward the roots gathering a grocery list of different minerals needed for growth and support. This process is similar to a hydrogen generator.

What are Artificial Leaf Hydrogen Generators?

Artificial Leaf Hydrogen Generators are one of the most efficient ways to generate hydrogen. The science is based on actual leaves of a tree. The process breaks down water into hydrogen and oxygen and water, much in the same way photosynthesis does in an actual leaf. Although the science has a ways to go, it is impressive to see how leaves of a tree can lead science to a greener future.

What is the purpose of hydrogen?

Hydrogen has many different jobs as it is one of the most common elements in all of plant life. One of the most efficient ways to get hydrogen is through plants. This is why Artificial Leaf Hydrogen Generators are becoming a thing. Most hydrogen is generated through the dissociation of water by photosynthesis, basically electrolysis. The hydrogen molecule, depending on the charge, can collect and transport messages throughout the plant in both directions.

How does all that hydrogen get into the soil?

As the hydrogen moves through the plant picking up various grocery lists of needed minerals, it makes its way to the roots where the photon pumps pump it out into the soil. Some of this hydrogen makes its way back into the plant via the photon pump, however, this time it’s carrying the mineral that it was sent for. The rest of the hydrogen stays behind and lingers in the soil as pH. But this is by no accident, the plant allows this hydrogen to escape to condition the soil for its maximum benefit.

Why is hydrogen important to plants?

Hydrogen is responsible for the collection and transportation of nutrients throughout the plant. Various conditions and disorders can disrupt these processes causing nutrient lockup. The most common misdiagnosis is pH issues. It’s really important that you familiarize yourself with all the different lookalike symptoms before assuming it’s a pH problem.

Commonly mistaken symptoms for pH issues:

  • Drought
  • Soil compaction
  • Wet conditions or standing water
  • Allelopathic chemicals
  • Herbicide injuries
  • Salt injuries
  • Fungal, viral, or bacterial infections
  • Insect injuries

Without previous knowledge or experience, these conditions would not be considered by the average gardener, landscaper, or arborist. Rarely in the landscape garden setting will pH actually be a problem.

Is it possible to change soil pH?

Due to the buffering capacity of most soils, it will be unlikely you can change the pH for longer than a few weeks. Most soil pH changes are made by farmers growing crops in high-yield fields that rotate crops regularly. On small residential gardens, it is unlikely you can effectively change the pH without causing physiological harm to established plants. Yes, you can change the pH of your soil, but luckily, the fail safe known as “soil buffering capacity” usually kicks in to save your plants.

Things that temporarily change soil pH

Nature and cultural practices can temporarily change the soil pH. Some of these things are:

  • Flooding
  • Mulching with green mulch
  • Over-mulching
  • Fertilizer use
  • Herbicide use
  • Washing vehicles in close proximity
  • Using sulfur as an insecticide
  • Acid washing in close proximity
  • Washing sidewalks and driveways
  • Construction projects using lime
  • Over-watering
  • Deicing salt.

All of these things should be considered when trying to identify or diagnose an issue.

When is it appropriate to change pH levels?

For gardeners, landscapers, or arborists, level-changing pH can cause a whole host of issues that may not be evident to the novice or professional. For instance, a change in the soil pH can cause anions, ions, and cations to switch roles causing nutrient lockout, a condition similar to the pH issues being addressed. As you can imagine, this would only exacerbate the issue at hand.

Conclusion

A gardener’s general rule thumb: if a plant was growing healthily and experienced a sudden pH problem, it’s unlikely to be a pH issue due to the soils buffering capacity. It’s more likely to be some other lookalike disease or disorder. Changing your soil pH should not be considered as a viable option to treat a disorder that looks like a nutrient lockout.

Links Used

https://www.cannagardening.com/introduction_ph
https://phys.org/news/2013-04-blueprint-cheap-hydrogen-production.html
https://www.sciencedirect.com/science/article/abs/pii/S1389556710000390
https://www.energy.gov/eere/fuelcells/hydrogen-production-electrolysis
https://www.besgroups.com/electrolytic-hydrogen-generator/
https://newatlas.com/energy/artificial-leaf-hydrogen-fuel/
https://www.biologycorner.com/worksheets/acids_bases_coloring.html
https://cdnsciencepub.com/doi/abs/10.1139/b74-133?journalCode=cjb1
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC438054/
https://organismalbio.biosci.gatech.edu/nutrition-transport-and-homeostasis/acquisition-of-nutrients-in-plants/
https://chemistry.stackexchange.com/questions/37053/what-is-difference-between-h%e2%81%ba-and-proton
https://en.wikipedia.org/wiki/Soil_acidificationhttps://www.agric.wa.gov.au/soil-acidity/soil-ph?page=0%2C1
http://herbicidesymptoms.ipm.ucanr.edu/HerbicideDamage/