No-Till Soil

I grew up on a grain farm. Growing up surrounded by farming, you become innately aware that there is a season and a time for everything. Seeds get sown in the spring. Crops get tended in the summer. Crops are harvested in the fall. After the harvest, the fields are tilled and turned under to prepare them for next spring’s seeds. This made sense. 

It wasn’t until I became more of an avid outdoor adventurer in my twenties and thirties that I began looking at nature a little differently. The most lush environments that I ever found myself in were the ones when I was buried deep in a forest somewhere. The forest floor was abundant with life and the springy, hummus-y soil was incredible to walk on, to touch, and to dig my fingers into. It was on one of these forays when the idea first occurred to me that the forest floor grew lush and abundant without the annual tilling that I had accepted as a part of the growing process. The seed stuck (pun intended) and when I first started growing crops commercially I began to look into a method I had heard of called No-Till. 

I didn’t start with No-Till methods right away. The particular piece of land that I grow on was a hay field that hadn’t been touched in approximately 30 years and there were a LOT of perennial weeds. Because I hadn’t fully researched No-Till at that point and because I was under a timeline to get the ground prepared for planting as quickly as possible, we tilled the ground. I don’t regret doing that and given the situation, I would do the same thing if I had to repeat it. However, now that I am in a position to use No-Till methods, this is the system that we use to prepare a new patch of ground for planting. 

So what is No-Till?

Well, it is exactly that. No-Till is a practice in which the soil is not tilled so that the biology of the soil structure and the layers of the soil are completely retained. In the forest, the leaves that fall from the trees and the plants that die down every year are left to decompose on the surface of the soil. The earthworms, bacteria, and microbes begin their work digesting and breaking down these plants. As the years go by, every layer is broken down even further and a new layer is formed on top. Given a few years, the soil starts to become much richer in organic matter. It retains more water and is lighter and fluffier in texture. If you think of soil in the terms of a forest floor, you can start to see how soil develops layers. Each layer of soil from the surface down has a different purpose and attracts different life forms living in it. 

When soil is tilled, one of the things that happens is a disruption of the soil layers. This sounds like it might not be a big deal but imagine what happens when an earthquake effects a city. Imagine the buildings that are knocked down. The materials strewn across the city streets. The people that are homeless and possible casualties. All of the materials that once created that city are still in the city. But they are no longer in the same place, or providing the same function. It will take time for the residents of that city to clean up the debris, put everything back in order, and complete the building process again before the inhabitants of that city can carry on with life as it was before the earthquake. 

It turns out that tilling the soil has the same effect on the soil inhabitants as it does on our hypothetical city dwellers. The contents of the soil, the building blocks, all still exist after the plow has been through, but the structure has been destroyed and the inhabitants have a lot of clean up to do before they can get back to doing their jobs with any efficiency. Not to mention the loss of life that will have occurred from the mechanical process of the tilling (worms cut up, microbes drying up on the surface). Our hypothetical earthquake ravages our city dwellers every single time the plow or rototill passes through. Plowing multiple times within a season keeps our city dwellers in a constant state of emergency, not to mention the loss of life that occurs each time. 

Soil biology has been overlooked for years. It has only recently  begun to be researched and as such, there is so much that we still don’t know about soil. What we think of as an inert substance that is a medium to keep a plant in place on a windy day, is actually filled with an overwhelmingly large and diverse life force. Scientists have only recently started to identify the vastness of the life.

Bacteria, protozoans, arthropods, fungi, archaea, and nematodes! Oh my!

When you hold a handful of soil, you are in fact holding hundreds of thousands of life forms. These life forms are responsible for creating soil structure, breaking down organic matter into forms that plants can use as nutrients, and much, much more. Fungi, for instance, forms a symbiotic relationship with plant roots that allows both to function at a higher level than they ever could on their own. 

The functions that soil performs and the relationships between soil and the plants that live in it are just beginning to be researched. And there is so much more to learn. 

In the meantime, I wanted to share the process that we use here on the farm to prepare a new patch of ground for growing. 

There are a couple of methods that can be used for killing back an existing crop (weeds or a cover crop) but the one that we employ most often is called Occultation. 

Occultation is, very simply, the blocking out of the sun. If you have ever left a bucket or planter on the grass for a few days, you will notice that the grass beneath it is yellow when you pick it back up. If you were to leave that item on the grass long enough, the plants below will starve from lack of sunlight (sunlight=photosynthesis=energy for plants). After the plants have died, the soil life begins to decompose the dead plants. 

We use a large black tarp for occultation in the field. The black tarp traps heat and speeds up the entire process of decomposition. In the heat of the summer, a patch of field can go from grass/weeds to ready to plant in as little as 6 weeks time. When it is cooler outside, it can take as much as 6 months to complete the process (ie over winter). The tarp also traps moisture beneath it which forces any weed seeds on the surface of the soil to germinate. These germinated seeds will then die out due to lack of sunshine. This process helps to clear the top surface of the soil from unwanted weed seeds before we plant. 

Before Occultation. This fall rye cover crop has died back after it was cut down in the summer.
During Occultation. This large black tarp is weighed down with rocks, tires, and pallets.
After Occultation. 6 weeks time in the heat of the summer and the remnants of the cover crop have disappeared. This soil is ready for planting

Weed seeds can lay dormant within the soil for up to 50 years. As soon as they have the right conditions, moisture and light, they will germinate. Every time the soil is tilled, new weed seeds are brought to the surface from the seed bank below. These seeds are exposed to sunlight and moisture and BAM! they geminate. This is why using no-till methods can also help to knock down the amount of weeding to be done on our farm. Once the seeds in the top couple of centimetres of soil have germinated and been killed, as long as the soil isn’t being disturbed below that level, new weed seeds will not be brought to the surface to germinate. That is not to say that we don’t spend any time weeding. We do. But most of the weeds on our established beds are weeds that have been blown in from the wind or have been brought in with compost (more on that in another post). We spend a lot more time weeding our newer beds and every year that goes by, we are able to spend less and less time weeding our established beds. 

There is so much more to soil and to No-Till methods than I can fill one blog post with. If you are interested in knowing more, reach out to me and I can recommend some fantastic books on the subject.