Koen van Seijen: What do you believe that is true about regenerative agriculture that others don’t believe to be true?
John Kempf: What I believe to be true about regenerative agriculture that is different from what many other people think about is what the engine of change actually is. And there is this idea within and particularly within the domain of organic and biological or regenerative agriculture that it takes healthy soil to grow healthy plants. And if you want to produce a disease and insect resistant crop as I’ve been talking about then you need to begin by focusing on soil health. I believe this is in fact. Completely inaccurate. It is not healthy soil that produces healthy plants. It is healthy plants which create healthy soil.
John Kempf: If you consider soil in the absence of plants then it is essentially decomposed rock. But it isn’t fact plants which through the process of photosynthesis and carbon sequestration producing sugars transmit these sugars out through the roots as root exodus that feeds all biology that contribute organic matter and create what we consider to be healthy soil.
John Kempf: So the foundational idea behind this is the realization that what we have come to accept as normal and as common is plants which are photo synthesising only about 15 to 20 percent of their inherent photosynthetic and genetic capacity that it is possible to manage nutrition by using foliar applications of specific nutrients and by using biologicals to in affect hack the system. Where we can increase the photosynthesis of a given plant or given crop from let’s say 20 percent up to 80 percent.
John Kempf: Which means that we quadruple the volume of sugars being produced in every 24 hour photo period.
John Kempf: But that quadrupling of sugars isn’t necessarily going to contribute to quadrupling the yield. You might get a 20 percent or 40 percent yield response but you won’t likely get a 4 x yield response. So all of the additional sugars that are produced from this spike in photosynthesis are sent out through the root system as root exudates to feed soil biology. This is how we can build soil organic matter by a third to a half a percentage point per year while we are growing a crop.
John Kempf: We can do this on strawberries in California where we have the soils till with a roto tiller every year it’s covered in plastic mulch it’s fumigated. There are no cover crops. There is a long list of sins committed against the soil health and strawberry production and in some of these fruit or vegetable ecosystems and yet we can build solid organic matter in these systems and sequester carbon simply by focusing on plant health.
John Kempf: So our emphasis our focus should not be on building soil health but instead on increasing plant health because healthy plants are the engine that create healthy soil.
Koen van Seijen: And I mean this this is going to go against quite a few people in a regenerative agriculture space including me, that always says focus on the soil. Focus on the soil but it’s you’re right. The plants and the trees create the soil. What does that mean for soil less growing in greenhouses hydroponics et.
John Kempf: Well the challenge with growing in hydroponics is that in most cases in many cases at least the biology that is needed to support Plant Health is absent in the system. So I put together a diagram called The Plant Health pyramid that we use to describe for growers how we observe the evolution of Plant Health at different stages different physiological processes how they become resistant to different types and groups of diseases and insects.
John Kempf: And what we’ve observed is that the first two levels of Plant Health the pyramid level 1 and level 2 where there is complete photosynthesis and the complete protein synthesis. These first two levels can be achieved simply by balancing plant chemistry and by balancing plant nutrition. So those first two levels can be achieved hydroponically. The upper two levels of the plant health pyramid where plants begin producing much higher concentrations and much higher levels of plant and secondary metabolites and all of these aromatic compounds that form the foundation of us being able to have a conversation about food as medicine. These compounds are only formed in higher levels when plants have an abundant microbial community in the root system and in the rhizosphere which precludes most hydroponic operations. So if we really want to have a conversation about producing healthy food that plants that are resistant to disease all diseases and all insects and achieving the upper levels of Plant Health pyramid that is generally quite unlikely to happen in a hydroponic system.