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lemons in the greenhouse

Ep. 2: Rediscovering Traditional Farming Knowledge amongst the Florida Citrus Greening Disease.

Remembering Regenerative Agriculture:

“Think outside the typical production box to find solutions.”

- Stephen Futch

“I used to think soil was something you stuck a plant in so it could hold up, and you put whatever it needed in it to grow that. Once I understood it’s the biology in the soil that feeds the plant, that it is its stomach, [things changed]”.

-Brad Turner

Brad Turner is a 4th generation grower with over 40 years of experience in the citrus industry, he understands the industry well. In 2015, like many of his neighbours, Brad was out of citrus due to HLB disease and high operating costs and was left without a job. During this hiatus, Brad stumbled upon a Ted talk on soil regeneration and that started a cascade of research. [1]

Dr. Brooke Hansen, Director of Sustainable Tourism at University of South Florida, says Regenerative Agriculture focuses on bottom up farming, on the vitality of the topsoil. [1]

“There is a huge difference between conventional agriculture and regenerative agriculture in terms of soil micro biodiversity. We need a supportive culture that values ecosystem services. We are not [just] growing trees and plants we are growing soil.”

-Dr. Brooke Hansen

In 2017 Brad heard of another Florida citrus farmer, Ed James who stumbled upon improvements in his citrus crop after using cover crops. Ed James was about to plough down his dying citrus crops and diversify his field as recommended by Industry specialists. He kept some of his old damaged groves and was applying cover crops to prepare his soil for the new plantings when he started to notice a marked improvement in his citrus trees recovery from HLB. Brad came to see this grove and was astonished. He says it was the most important day of his life, aside from his wedding day. [1]

Inspired, Brad bought an old tract of dying citrus grove and started doing research trials using cover crops. He was interested in the nearby forest grove that had wild citrus growing in it. Upon leaf sap analysis of the wild citrus, he found that their Calcium levels were extremely high which is very rare to see in commercial citrus. Using soil regeneration techniques, Brad took samples of the soil near the root zone (rhizosphere) and propagated the microbes at home.

To do this he: took the inoculum and mixed it with earthworm compost and fish hydrolysate in a 5 gallon bucket. He let this sit for a month or two and then poured the material into a mesh bag and dropped it into a 250 gallon bucket of water being aerated by a compost tea aerator. This way, the bacteria in the inoculum replicate every 20 minutes. In a couple days he takes the brewed liquid and sprays it as a foliar and ground spray all over the trees. This technique can be thought of as replenishing the plants damaged immune system, or microbiome.

In ONE YEAR they saw improvements to the size of the new growth; they knew they were on the right track. [1]

In traditional agriculture, farm input costs of fertilisers and pesticides can be upwards of $2500/acre/year. Using this alternative method, Brad is spending less than half that at $1000/acre/year. This has a compounding effect year after year so that less and less money is spent as less inputs are needed. What he also found was as the Brix level increased to 13, no other insect pests predated on the plant except for grasshoppers. At a rare, but occasional Brix of 15, no insect predation was occurring at all. [1]

What is important here is that as the plant's health increased, so did the amount of secondary metabolites it produced to defend itself from psyllids that vector HLB. A Brix metre is a cheap and cost effective way to measure all the soluble solids in the plant leaf sap or the fruit using light-refracting spectrometry. The more soluble solids in the sap, the more complex metabolites the plant is producing, which is a proxy for photosynthetic capacity and nutrient availability.

In May 2018 (when Brad bought the property) 21 inches of rainfall left enough standing water to kill half of his trees, 3 years later (2021) 21 inches of rain completely soaked into the soil. This is due to increases in Organic Matter(OM) from the increased root biomass of the cover crops providing the inoculated beneficial microbes with root exudates (polysaccharides) to feed on. To put into context, 1% increase in OM can hold 18,000 gallons of water per acre. [1]

For a microscopic video view of a growing root and its surrounding microbes see here.

Meanwhile… in the Florida Citrus Production Guide [2] they say, “Currently there is no proven management option for the prevention of HLB-associated root loss… The largest contributor to root health that will affect pests, pathogens and the tree itself is the soil and water at the site”. Really?

“Good Soil health is the key to affordable, sustainable agriculture. It works and it is inexpensive. I’m confident that in 10 years this will be the norm, we will see plants growing all up and down, everywhere”.

-Brad Turner

So, is the cure to HLB cover crops and beneficial microbes? Sounds very simple, why hasn’t it been talked about before? Well, it has…

In 1930, E.F. DeBusk a Florida Citrus Hall of Fame inductee, Extension Specialist in Citriculture, from the University of Florida wrote an article calling upon the need for cover cropping and mulching in citrus production. [3]

In 1985, a seminal book titled “Healthy Crops; a New Agricultural Revolution” was published in France (translated text available here), by a scientist named Francis Chaboussou. Francis coined the term “Trophobiosis Theory”, meaning a “pest starves on a healthy plant”. Following in his footsteps are research done in published papers in 2008, and 2021 about the effect pesticides have on root biota as well as the similarities that root rhizosphere ecology has to our digestive systems (2013). Francis also wrote another book entitled: “Les Plantes Malades des Pesticides” (plants sick from pesticides). Francis was born in 1908 and dedicated 40 years of his life to researching these interactions. He is quoted saying:

“What makes plants attractive to parasites is the excessive amount of soluble substances in their tissues (mineral salts, amino acids, reducing sugars), and insufficient proteosynthesis, the true key to health. Synthetic herbicides and pesticides are responsible for inhibiting proteosynthesis, by directly poisoning the plant, but also indirectly by destroying soil micro-organisms”.

Pesticides tragically have a history in war. Between 1961 and 1971 the US government sprayed over 20 million gallons of herbicides manufactured by Monsanto and Dow Chemical over Vietnam, Cambodia and Laos. 400,000 people were killed as a result of their exposure to these agro-chemicals and their effects persisted in the environment for many years: causing deformations, neurological problems and birth defects. Half a million children suffered from birth defects in Vietnam and 2 million people got cancer as a result of the pesticide dumping. The chemicals used by Nazi Germany were manufactured by an insecticide maker as well. [9]

What should we do?

Move away from a mindset of elimination to germination!

Farming and housekeeping are not the same thing.

Left: A citrus grove with a diversity of cover crops, Right: a traditional citrus field.

~Living in flow with nature~

If you haven't read Episode 1 click here

Article Written by: Odette Hobbis


[1] 2021 Agricultural Environmental Award - Brad Turner

[2] Production Guide - University of Florida, Institute of Food and Agricultural Sciences

[3] The Need of Organic Matter in Fertilizing Citrus Trees

[4] Healthy Crops

[5] Paull, J. (2008). Trophobiosis Theory: A Pest Starves on a Healthy Plant. Journal of Biodynamic Agriculture Australia, 76, 51–54. Retrieved from

[6] Reid, T. E., Kavamura, V. N., Abadie, M., Torres-Ballesteros, A., Pawlett, M., Clark, I. M., … Mauchline, T. H. (2021). Inorganic Chemical Fertilizer Application to Wheat Reduces the Abundance of Putative Plant Growth-Promoting Rhizobacteria. Frontiers in Microbiology, 12. Retrieved from:

[7] Ramírez-Puebla, S. T., Servín-Garcidueñas, L. E., Jiménez-Marín, B., Bolaños, L. M., Rosenblueth, M., Martínez, J., Rogel, M. A., Ormeño-Orrillo, E., & Martínez-Romero, E. (2013). Gut and root microbiota commonalities. Applied and Environmental Microbiology, 79(1), 2–9. Retrieved from: Gut and Root Microbiota Commonalities | Applied and Environmental Microbiology

[8] Bacteria at root .mov

[9] Agent Orange - HISTORY

For more information on Brad Turner, visit his website at

Interested to Learn more about Regenerative Agriculture and Agro-Chemicals effect on the Soil? Visit McGill’s “Ecological Agriculture Projects” website about: Agricultural chemicals and the soil

Interested to learn more about Soil Biology? See Elaine Ingham, someone who helped inspire Brad Turner:

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