The 2nd Principle for Healthy Soil: Keeping the Soil Planted

In our previous article, we explained why it’s important to keep the soil covered and how to do it right.  We will now look at the second principle of conservation agriculture – keeping the soil covered. This is another crucial step for ensuring good soil microbiology which directly translates into healthier soil and more nutrients for your plants, whether that’s in your garden or in large agricultural set-ups.

Again, just like with keeping the soil covered, this is not so much a recent discovery, but rather a re-discovery and reaffirmation of old agricultural practices. There are records dating way back that depict farmers using crop rotations, succession plating or cover crops to ensure better yields. But scientists are only now beginning to unveil the complex relationships between plants and the microbes and fungi living in the soil.

Why is it important to keep the soil planted?

The first step in understanding the importance of keeping the soil covered is to understand why roots in the soil help it have a long and healthy life. Because yes, the soil is alive and soil can get damaged and ultimately die.

Photosynthesis is a term that everyone is familiar with. In very simple terms, plants use photons from sunlight to synthesize carbohydrates from carbon dioxide and water. Some of these carbohydrates are used by the plant to help itself grow, while some of these chemical compounds are exuded through the roots in the soil, feeding it in the process.

Each type of plant feeds the bacteria and fungi in the soil a particular type of exudate. Each microbe in the soil needs a different exudate to thrive and to supply its own chemicals to the plant in return. The relationship between the plant and the soil is symbiotic, and one cannot thrive without the other. That being said, the way in which this relationship is maintained has a direct effect on the quality of the soil.

The best way to understand the relationship between the two is to imagine the soil as a human being. Humans need food to thrive. But what if they ate only one type of food their whole life? They might live for a while, but they won’t be healthy. The soil needs a wide range of food to get all the nutrients and energy it needs, just like a human needs nutritional diversity in order to stay healthy and productive. The microbes and fungi in the soil can get some extra nutrients from the mulch you apply, but the most important food source for them are the exudates fed by the plant roots.

The path of an exudate

If we are to look at one single microorganism, after consuming one exudate supplied by a root, that food will be converted into energy. The energy will then be used to supply itself with more nutrients from the soil. In the circle of life, that microorganism will get ingested by a bigger organism, such as an earthworm. The worm will then be eaten by a chicken that will later lay an egg that will end up someone’s breakfast.

In its path, the exudate released by the plant root will end up in your body. A particle that started as sunlight and water becomes part of the chain of life. All the carbon-based life forms on earth are intertwined, and the common factor between all of them is the soil.

When the soil gets filled with organic matter, it feeds all the other creatures with carbon. We can consider soil to be healthy not just from the amount of organic matter stored in it, but by the number of live organisms depending on it. Plants, through their photosynthesis, stay at the base of all life.

The relationship between plants and soil

I’m sure that by now you understand that plants are essential in our day-to-day life. Living plants are the best thing to use if you want to supply the soil with direct nutrients. They charge it, and they drive more life forms towards it.

Photosynthesis, aside from giving us oxygen, also reduced the temperature on the planet by absorbing some of the sun’s energy through their leaves and by sequestering CO2 from the atmosphere and storing it in the ground as carbohydrates. Without enough plants, temperatures would be unbearable.

Whenever you’re cleaning out your garden beds, remember that because the roots supply a high amount of carbon for a long time, it’s best to leave them in when removing a plant. They will continue to do their job that way. Living plant roots supply water, but even when they start dying, they will provide direct nutrients to every microorganism around them. So, while it’s in our power to do so, you should never let the soil be barren. It will start “eating itself” and release carbon dioxide into the air. Normally, plants would catch the carbon dioxide and repurpose it, but in their absence, it just escapes into the atmosphere.

Cover crops

Cover crops, as the name suggests, are crops whose single purpose is to cover the soil between other crops that are grown for food or selling. Cover cropping barren land is growing in popularity lately, as gardeners and farmers all around the world have started to see the benefits: less wind and rain erosion, more root exudates that feed the soil and more organic matter concentrations in soil tests.

If you don’t have a crop planned for a patch of garden, you can just plant cover crops. They don’t need much work to thrive. Even after harvesting, you can quickly plant a cover crop in place of the ones you just harvested. You can use them temporarily between your seasonal crops, and that way the soil will never stay without fresh roots growing in it.

Farmers who practice conservation agriculture prefer to harvest and plant cover crops on the same day. Transplants are a fantastic way to do this.  They are an uncomplicated way to fill empty soil immediately with plants that can already photosynthesize. Humans have this wonderful ability to help when the soil can’t get what it needs straight from nature.

Another trick is to under sow or over sow cover crops into crops that are already planted, such as winter or fall cover crops among your already planted broccoli. Your plants must already be photosynthesizing before you plant cover crops between them, but you’ll have to do it early enough before they take over the space.

Some of the most popular cover crops used are clovers, winter ryegrass, buckwheat, radishes and peas. They all have specific benefits and methods of action. Just look at how these radishes drilled through our hard clay soil, helping us break compaction.

There are many ways to intertwine cover crops with regular crops, but even if you don’t choose this method, and you take a couple of days to replant empty soil, you’re still doing it right.

Crop rotation

Keeping living roots in the soil is important, but as we said above, feeding it several types of organic matter is vital for soil health. Rotating your crops regularly is one of the best ways to do so. Not just that it help the soil get a diverse diet, but it also helps with preventing crop diseases. Each plant disease prefers a particular crop, and if it doesn’t get fed, it will die out.

The main rule for crop rotation is to move your planting spots every year in such a way as to avoid the same family of plants growing in the same place for three years. Also, learn what type of plants feed nitrogen to the soil. One year you can plant crops that feed on nitrogen, and the following year is best to plant crops that supply nitrogen. That way the soil stays healthy.

I really hope this article was able to give you a glimpse into how keeping the soil planted will help you improve your soil health and how it all works. Although the biological mechanisms at play here are very complex, I tried my best to simplify things and focus on the big picture, to help everyone understand these processes better.

Leave us a comment below if you learned anything new or if there’s anything you want to add.