Where do plants get their nutrients?

Jan Baptista Van Helmont                       Helmont’s Willow Tree Experiment                    

The 5-year Willow Tree experiment is perhaps Helmont’s best-known scientific work. Helmont planted a 5-pound willow in an earthen pot with 200 pounds of dried soil. Over the next five-year period he added nothing to the clay pot but distilled rainwater. After five years, the tree weighed 169 pounds, but the soil had lost only 2 ounces. He concludes, “164 pounds of wood, bark, and roots developed from the added water. His work failed to add in the weight of the leaves produced each year. But, to give the guy, a little credit, the microscope had not been invented yet, so his knowledge of photosynthesis was somewhat limited.

A couple of things to look at with what Helmont’s research discovered: 1. He did not know the dust particles in the air contained nutrients 2. Some years after Helmont’s experiment and the invention of the microscope, science discovered photosynthesis.  We now know, of course, that this is the process by which plants utilize sunlight to produce carbohydrates for growth and energy. The water used in the experiment was distilled rainwater, so it would not have contained nutrients that could have added size to the tree.

Another element that we need to look at is the amount of root mass produced. Remember what’s above ground is equal to what’s below ground. This is a critical point to remember with sustainable agriculture as above-ground tonnage production matches underground organic matter production.  Furthermore, soil organic matter contains the same nitrogen, phosphorus, calcium, zinc, and manganese, along with the other essential nutrients. As we grow healthy crops, we are leaving balanced nutrients as soil organic matter.  This organic matter is food for the soil food web that breaks down, digests, and decomposes SOM into soluble plant foods.  In Van Helmont’s test, there was an increase of 3280% over the five years without adding additional nutrients. As remarkable as that increase is, today, with annual crops, the percentages are even higher when going from a bag of seed to tons of material harvested per acre. Other contributions to the Helmont experiment came about because of the diverse populations of soil microbes in the soil. Additionally, bacteria and actinomycetes, smaller in number but larger than the bacteria in size. Fungus population numbers are lower; however, they can dominate the soil biomass in no-till environments.

Healthy soils contain all of the above creations. Healthy soils contain more microbes in a teaspoon than there are people on the earth. We must stipulate healthy soils can provide 8 to 15 tons of bacteria, fungi, protozoa, nematodes, earthworms, and arthropods on a per-acre basis. It bears mentioning that “healthy soils” means soils balanced with the proper levels and or ratios of soluble calcium. Of course, there are other essential nutrients, but calcium is the “trucker of nutrients.”  and without adequate calcium levels, there will always be nutrient availability issues. According to “Phillips (2017) in Mycorrhizal Planet:

“Plant roots can only “shop locally” for so long, especially when it comes to less mobile nutrients. Dig up a mass of roots, and what appears to be a considerable surface area for absorption only reaches so far. Take this to the macro level and even a fibrous root system occupies at most 3 percent of the total soil volume. Left to their own devices, roots can access 1 to perhaps 2 cubic centimeters beyond the actual root epidermis to directly uptake mineralized nutrients” (Phillips, p50).

To keep this soil system moving in the right direction, start with calcium.