My journey to regenerative agronomy, and some thoughts on how to loosen tight soils
My journey from a synthetic agriculture mindset to a new and profitable approach to farming began many years ago, but my introduction to conventional ag occurred more than 40 years ago when I bought a crop-dusting business from my father and uncle. I remember my dad telling me that we were going to save the world’s food supply by eradicating of all the pests and diseases attacking our crops. Being raised in that atmosphere, I believed him.
I later sold the business to start a ground-spraying business, since I was not a pilot and had a hard time paying my pilots more than I was making. My transition to ground spraying was relatively smooth; my client base was already there due to my relationships from my crop-dusting business. But I soon realized that this path wasn’t what I wanted, either.
I decided to get my Pest Control Advisor license and was hired by a local retailer in 2000. In my early years as an advisor, I still had the mindset that we were going to save the world with chemicals, although I did feel nutrition was the key to obtaining clients through increased yields. So, I focused on nutrition right from the onset of my career.
In 2002 I was introduced to Dr. Thomas Yamashita in Turlock, California. He had started a crop nutrition business that was trying to work in convergence with nature. Dr. Tom was teaching things outside the normal paradigm. His message didn’t set in with most of my colleagues, but I saw value in what he was teaching.
I focused on permanent crops in our area — particularly almonds and walnuts. Though I still advised on crops such as rice, alfalfa, corn, beans, sunflowers, seed onions, cotton and tomatoes, I loved working with the permanent crops since it was easier to get the grower to implement inputs for soil health. As I advanced as an advisor, I was always open to new ideas and was constantly trialing new products. I saw the value in seaweed, humic acids and biological products that were coming onto the market. These all helped to enhance the plant’s ability to combat diseases and abiotic stresses.
But it wasn’t until I attended the Acres U.S.A. Healthy Soil Summit in 2019 in Davis, California, that I finally got a grasp on how to get the most value from these tools. I learned there from John Kempf, Gary Zimmer, Glen Rabenberg, Brendon Rockey and others, and left with a handful of influential books, including Gabe Brown’s Dirt to Soil and Gary Zimmer’s The Biological Farmer and Advancing Biological Farming. I’ve attended many Acres U.S.A. events since, always coming home with more insight and enthusiasm. For the 2022 Healthy Soils Summit in Sacramento I was asked to host the farm tour to share some of the successes we have had.
I have been privileged to help growers who only knew chemical farming methods transition to regenerative inputs and even to organic certification. We have experienced a big drop in our reliance on fungicides and insecticide treatments, along with yield increases, thus giving my growers the confidence to continue in the path we are taking. Implementing changes usually takes a couple of years — most likely three years to really see the difference.
The most important lesson is treating the soil as if it’s a living organism and knowing what inputs or cultural practices enhance or deter its progress. Seeing the healing qualities that nature has to offer is astounding, and we need to learn to not get in the way.
But we can speed up the recovery with certain inputs or cultural practices. I learned from John Kempf the importance of foliar feeding in order to keep the plant-factory producing sugars to increase Brix and to feed biology. Gary Zimmer’s books, along with Arden Anderson’s Science in Agriculture and Michael Astera’s The Ideal Soil, helped me learn how to amend the soil correctly to create the balance necessary for optimum soil health. I’ve also benefited from David Knaus’s work on how excesses and poor ratios in the plant can predict susceptibility to disease and insect pressure.
I believe that the transition to regenerative can be done without sacrificing yield and can bring profitability back to the farm. Many growers are more ready than ever to make the transition, due to the high input prices of synthetic fertilizers. I also think the pressure of the European Union on wanting to lower MLRs (Minimum Residue Levels) will force the hand of many producers to change their ways. The key will be to create guidance to make the transition as painless as possible and to create enthusiasm.
One of the most satisfying things I’ve experienced as an agronomist is hearing a grower tell me, “You’ve made farming fun again.” I’d have to say the same about my experience with the Acres U.S.A. community. I’m looking forward to sharing more of my experiences.
Loosening Tight Soils
When I visit a ranch for the first time that has been unproductive and riddled with disease, I often discover that its biggest problem is that it has a tight, compacted soil. The first thing out of my pickup is my penetrometer (everyone should have one!). It’s a tool you can use to monitor your progress in reducing compaction. Here in the Sacramento Valley, most of our soils are high in magnesium, with areas of high sodium, so sticky, tight soils are common.
The next tool out of the pickup is my shovel or soil-core probe. Soil sampling is a must for making sound decisions. I will generally ask the lab for the Mehlich-III extraction method so I can correlate methods to correct soils from Michael Astera’s The Ideal Soil v2.0. This book has easy-to-understand strategies for balancing soils. The formulas are based on Dr. William Albrecht’s and Dr. Carey Reams’ findings. Astera combines the best of these two great pioneers, in my opinion.
Once we get our soil sample back, we can start to make decisions on what amendments are best for that field. The physical nature of the soil is critical in allowing the soil to breathe, so we must amend it properly. First and foremost, the Ca:Mg should to be addressed. There are many other ratios to consider, but improper Ca:Mg will create antagonistic effects with many other nutrients — particularly nitrogen and potassium, which are huge cost to growers. In general, calcium tends to loosen soil while magnesium tends to make it tighter. I think that a Ca:Mg ratio of 7:1 is needed for higher-cation-exchange soils to allow the calcium to loosen the soil properly. In lower-CEC soils, a lower ratio is desired — possibly 5:1 — to allow the magnesium to keep the soil tighter.
We have many choices of products to work with: gypsum, limestone, dolomitic lime, soft rock phosphate, sulfur, compost and leonardite, along with many microelements, including zinc, iron, manganese, boron, copper and others. Proper ratios are extremely important for correcting a soil, and it seems that excesses in the soil create more of a problem than the deficiencies.
If soil needs big changes, I generally don’t like amending in large amounts. I feel the large rates can create some temporary antagonistic tie ups. If the grower is wanting to maintain yields, I’m careful to not recommend much more than a ton of gypsum or lime; in most cases it’s half that amount. I will recommend large inputs if it is a pre-plant application where some tillage is involved. I feel the most important aspect of your amendment is the quality and particle size (sieve mesh) — the smaller particle size will give you a much bigger bang for every pound applied.
A perfect example of this occurred just last year. I had two growers that needed to apply lime. Grower A found some limestone for $49 a ton. Grower B spent $75 a ton for his. But only 42 percent of Grower A’s limestone passed through 100-mesh sieves, whereas Grower B’s had 81 percent pass through. Who got the better value? The answer is Grower B — when you do the calculations for effective calcium, Grower A paid 11.2 cents per pound of effective calcium while Grower B paid 11.0 cents. The $75-a-ton limestone also had slightly higher CaCO3, by about 3.5 percent (90 percent vs. 87). The bottom line is that Grower B can apply two thirds of the amount and should still see better results.
We can’t stop there, though. Especially in soils that have poor ratios, we need to introduce biology. I have found that biology is more important than chemistry in poor soils for creating air space in the soil profile. If you add biology, you can usually still get desirable yields while waiting for the mineral amendments — which need to be added year after year to fix your ratios — to take effect.
Compost is an important starter kit for biology, but you should get a current analysis in order to match the needs of your soil. I’ve seen growers overapply compost and create a problem greater than the one they started with. The most common problem is sodium levels in some manure-based composts, but I’ve also seen high potassium and copper levels in compost; just beware of how much you’re applying. I feel a two- to three-ton application is all that is needed to jumpstart biology.
Other tools that are important are humic products, such as a dry leonardite and its liquid extractions, humic and fulvic acid. I have also incorporated other carbon products such as ulmic acid and biochar. I feel these carbon products help buffer microbe-killing salts and create exchange sites for many minerals, as well as housing for the biology.
When adding these various organic acids, I will occasionally add some molasses and inoculate with some beneficial bacteria. Depending on whether it’s a permanent crop or a field crop, I will try to manipulate the fungal:bacterial ratio, with permanent crops desiring much more fungi compared to field crops.
I know this sounds like a lot, but there are many products that can be stacked with each other to help minimize the number of applications. When implementing these inputs, the grower will usually see a visual response with their crop in year one, but to create a disease-suppressive soil will normally take three years. Air exchange in the soil profile enhances paramagnetism, which some argue is a big factor in the plant’s ability to communicate with the soil. This system will have minimal disease because the biology is working in concert with the plant, thus creating a much better immune response. It seems like the same thing is happening in us — those who have a healthy gut biome will generally have a much better immune system; our gut is our soil.
With this system put in place, I’ve seen big reductions on fungicide and insecticide applications. Nature’s ability to heal itself never ceases to amaze me; we just need to not get in its way. Regenerative agriculture will be instrumental in reducing our toxic environment — and in fixing our troubled healthcare system by producing clean, nutrient-dense foods.
Jim Pingrey is an agronomic consultant in northern California’s Sacramento Valley.
