In the 40’s in post-war Japan an agricultural scientist turned his back on conventional practices and started an interesting experiment. Masanobu Fukuoka wanted to try agriculture the natural way; without ploughing, without herbicides and pesticides, and even without excessive weeding of his fields. The result? The crops seemed to be stronger and more resilient, and his costs to produce went down significantly. Basically, by doing nothing it was perfectly viable to grow crops. Fukuoka named his method “Shizen Noho”, or “Do-nothing farming”. Being kind to soil seems to bear fruits.
Although it took a while longer for the concept (or variants thereof) to be used more widely in the rest of the world, the first long term studies on the effects of this method of agriculture seem to be in. It seems the harvest will be reduced, especially the first couple years. However, in the long term the soil will be less eroded, less exhausted, less polluted and the nitrogen emissions will be reduced. It seems to be a moral choice more than anything: Both methods are sustainable income wise, but one yields less profits but leaves the land in a better condition. Short term profit versus long term sustainability, a theme these days. But what is the reason behind this? Let’s take a quick trip through the ecological importance of soil.
Layers and horizons
Soil comes in layers. Layers with different colours, different compositions and different functions. Leaf litter or wood chips on the ground level? Prevents moisture from escaping the soil as fast and provides material to break down for future plants. A black layer of pure humus? Incredibly rich in nutrients and essential to plant life. These layers are a result of the environment and the ecosystem that the soil is in, and the type of layers also determine a lot about the ecosystem above ground. Many mechanical and biological processes lead to the forming of these layers. The mechanical processes are more responsible for the forming of the substrate itself, sometimes over centuries. The biological processes, however, can appear but also disappear in a rather short span of time.
The critters under our feet
When we talk about biodiversity, the image that most people will get in their heads is a view of a lush jungle, every plant a different species and animals abundant. Something which might get overlooked, however is the very richness of diversity under our direct feet. Although it is difficult to quantify exactly, soil diversity compromises a large part of biodiversity, and strong relations between soil biodiversity and ecosystem services have been found. Much like habitat types above ground are there habitat types below ground, with specific organisms living at different depths and heights. These organisms provide ecosystem services as mentioned before, think of things such as breaking down organic material, fixating nitrogen for plant use or causing bioturbation in the soil so that new material and nutrients are available to crops planted there. Basically the things we do to till ground happen naturally as well, albeit at a different pace. This isn’t limited to the occasional worm or mole, a rich variety of springtails, fungi, bacteria assist as well.
So what are we trying to do when tilling a field, covering it with manure or spraying the area with pesticides? Basically we are trying to create the ideal environment for the crop that we want to grow there to grow. But in doing so, we are causing a massive distortion to the subterranean ecosystem. Within evolutionary biology there is a fine line between enough distortion to promote biodiversity and too much distortion which causes the habitat to be too unsuitable for many species to thrive in. Our current way of tilling seems to look more and more like the latter. I think it could also be useful to think about why that crop doesn’t grow there. What are the dynamics of the soil system in that field? What circumstances are needed to cause the soil to become suitable for the crop you want to grow? Or maybe we’re trying to force something to grow here which (logically) shouldn’t grow well here. Be kind to the soil. Be kind and it may give us something in return, for generations to come.