A healthy soil is an incredibly complex ecosystem that we know very little about. There are millions and millions of interactions that occur within our soils. It is more complex and busier than a bookie in Vegas on fight night. I call this My Secret Underground Black Market and it is controlled by the plants. Let’s just call them the Mob! How does this mob of plants control the black market? It is because they produce and control all of the currency. Everyone in the soil wants sugar. Sugar is the currency, the sustenance of life and it is only produced by plants. There are millions of soil organisms that constantly broker deals with the mob in the quest to get sugar.
Every critter in the soil needs it. As an example, we all know legumes are plants that are known to produce nitrogen. It is not actually the plant that acquires the N. There is a type of bacteria that works with the different types of legumes and forms nodules on their roots. It is the bacteria that gets the N from the air and then trades a molecule of N with the plant in return for a molecule of sugar — a fair trade all around.
I do not have enough time or knowledge to get into all of the different critters and all of the different interactions. It is incredibly complex. I would, however, like to single out one other critter that we have in our soil that does not get enough recognition for all of its hard work.
Mycorrhiza fungi is the mob’s No. 1 man. It is in charge of transportation and distribution. This fungus sets up a system of arbuscules which are like root hairs that can extend the reach of the plant’s root system up to 1,000 times. In exchange for sugar, this fungus can transport nutrients directly to the plant’s root system. It acts like a system of root extensions that help to gather the needed nutrients. This is truly a symbiotic relationship benefiting both parties and it only works if both sides do their part.
Every plant is approximately 45 per cent carbon, 45 per cent oxygen, six per cent hydrogen and 1.5 per cent nitrogen. And 97.5 per cent of that comes from the air. (So why is it that we add nutrients?) Only the remaining 2.5 per cent needs to come from the soil. Nature has had this figured out long before we came along with soil amendments.
This is where our mycorrhiza fungi comes in. It spreads though the soil and gathers everything else. It actually has the ability to decompose stone and extract micronutrients from it for the plants. This is the ultimate courier in the black market system. Whatever the plant needs, the mycorrhiza fungi can get it.
If one arbuscule of the mycorrhiza runs out of nutrients in its location, the plant will cut off its supply of sugar and let it die, and send sugar to other arbuscules that are bringing in supplies. There is no free ride when dealing with the mob.
There are four big benefits that we get as ranchers from this symbiotic relationship. Obviously, with a continuous supply of nutrients, we will get more yield from our pastures without the added cost of supplying fertilizers. More growth with less cost is always good for the bottom line.
Second, the hard-to-get phosphorus is released by the fungus. Phosphorus is usually bound up in the soil and is unavailable for the plants. Our friendly neighbourhood fungus comes to the rescue and can broker a deal for the rare commodity, a win for us ranchers.
Our third benefit is drought resilience. When the times turn dry (and the soil gets hit with prohibition laws), the small plant root system can no longer reach its favourite drink. So our extensive network of fungus starts supplying water to the mob. There is nothing they will not do in the quest for sugar.
This underground black market will always find a way. If you think about it, it is a life or death situation. If the plant can’t get water, it stops handing out sugar. Without sugar, our fungus will die so it is pretty important all around that this symbiotic relationship stays strong. We all know that one-sided relationships never last.
Mycorrhiza fungi is also the enforcer.
The fourth benefit that we receive is disease resistance. This tough guy for the mob helps to fight off a variety of diseases and pests that can be detrimental to the plants. They strengthen and protect the mob from bad guys. It can also transport information to other plants warning them about an incoming disease and the next plant over will start building up resistance before the parasite or disease even reaches it. So not only is the mycorrhiza fungi the highway it is also the internet of the soil web sending information back and forth. Talk about your world wide web!
Here is the kicker. If the plants are weak, they can’t spare any sugar. With no sugar there is no fungus. The system fails. All the more reason to maintain healthy pastures. An overgrazed pasture has a poorly functioning black market. This is why there is more mycorrhiza fungi present in rotationally managed pastures than in continuously managed ones; the stronger the plants, the stronger the fungus. So be sure to plan for short graze periods and long rest periods. Remember, this black market depends on you.
What do you think would happen if you added in chemical fertilizer to the mixture? The plants get excess nutrients for free so the fungus is out of a job. The black market is disrupted and the fungus dies. Then when the drought hits, who is there to supply the plants with the hard to reach moisture, or the other needed micronutrients? What happens when you then stop supplying the fertility? How about if a fungicide is added to the system? I think you get my point.
This secret underground black market it pretty important to our pastures. This is just one example of the many trade deals brokered by the mob. There are millions of interactions that occur beneath our feet that we are completely unaware of. Take care of your black market. The survival of the whole system depends on it.