Last Thursday I was lucky to be able to attend the Soil and Nutrition conference, sponsored by the Bionutrient Food Association and NOFA/Mass. During the lunch break, I sat down with the presenter John Kempf to ask him some questions and talk with him about some of the issues we struggle with in our pasture and hayfields. We are challenged by having forage that is very high in protein (which is great!) but too low in sugars and starches. Before John Kempf became a soil consultant, he worked as a forage consultant for grass-based dairies and helped those dairies build the soils and forage that was necessary to support their cows.
He said that he knew the key was to help with the immediate energy needs in the plant, which would in turn help the soil over time. 70% of the sugars in a plant are exuded through the roots to feed soil biology, this is part of the plant-soil relationship. Therefore, plants must be incredibly sugar-rich (highly photosynthetic) in order to be able to give up 70% of its sugar and still have enough in order to feed animals (in the case of forage) or grow a fruit (in the case of veggies/fruit).
John explained that there are three ways to build soil organic matter. The first is to import it (in the case of applying minerals, purchasing compost, etc). The second is to produce it yourself (by using cover crops, fresh manure, or making your own composted manure). The third is through carbon induction. Carbon induction is the process by which healthy plants send out root exudates. This is by far the most efficient method, it is also the least expensive and can be the fastest as well, if the plants are well fed.
He explained that plants have low sugar production when they are not photosynthesizing at a high level. Nutrients are necessary for optimum photosynthesis. “If photosynthesis is an engine, nutrients are the key”. It is extremely common for less-than-optimum photosynthesis because most soils today are nutritionally depleted, due to heavy tillage, herbicides, continual harvesting of hay, etc. and other conventional management tools over the past several decades.
He suggests using Photo Mag as a foliar spray – apply to hay fields immediately after they are cut and to pastures the night before (or a few nights before) the cows enter that paddock. In the 24-hour photosynthetic cycle, the production peak is during the day, transport peak is in the evening, and growth peak is between 3 and 8am (when most growth happens). He suggested we experiment with it – do it during one pass through in our rotation, or some hay fields and not others so we can compare. He seemed very confident that it would help, said that he has seen it make the difference for many farmers. It would be necessary to do this foliar spray for a few seasons, until the soils are healthy again and the plants’ brix reading is high, but says that of all the nutrient applications that we could do, this would be the fastest and most effective. The magnesium in the spray will “jump start photosynthesis”. He said, “it’s a trigger to enhance the efficiency of the entire system”.
We also discussed spraying raw milk on fields. Spraying milk is good because of the enzymes, probiotics, but most of all because of the fat that can all be used to feed and enhance soil life. If you can apply milk with good fat content, the plants can absorb it and it will boost plant energy. However, you can overdo it with raw milk spraying because you can throw the bacterial species out of whack in the soil. The probiotics in raw milk are so powerful, that they can actually outcompete soil microorganisms!
The major take home message that I got from the workshop was: healthy soils –> healthy crops, but ALSO healthy crops –> healthy soils. It goes both ways.