Dirt.
By: Gregg Deponte
Tags: Farmers, Farm, Regenerative Agriculture, Soil Health

Playing in the dirt is a favorite past time of youth. From playing with toy trucks in the mud, to riding bicycles on dirt tracks, or playing in my grandpa’s garden, I have fond memories of being a child and getting dirty. Watching my own kids play in the dirt brings back a lot of those memories for me. When my wife and I bought our home in the Seattle area 10 years ago and started planting a garden, I began to look at it much differently. Most people don’t really think about it, but dirt in the form of soil is alive. During my time in academia, soil was discussed as the medium that holds nutrients and that plants grow in. Our perception of soil has definitely changed from then. Now, we view it as being full of life. It is said that one teaspoon of soil contains more living organisms than all the people in the world. Without that life, it is just dirt. One could devote a life time to study soil and still not understand every aspect of it due to the sheer volume of information and because discoveries about it are still being to this day. Fortunately though, we don’t need to have a PhD in agronomy to use the information out there. In following the 5 key principles of soil health we can manage the land to be productive and profitable. And through using observation, we can have a good idea of how we are doing at managing the soil.

Before I head into the principles of soil health, a quick discussion on soil organic matter (SOM). SOM is all of the organic matter in the soil from plant and animals in various states of decomposition. As I discussed in the last month’s article on water, a 1% increase in SOM allows the soil to hold up to 25,000 gallons more water per acre. It also increases the soil’s fertility by allowing more nutrients to be retained, reduces soil compaction and crusting, and helps to build and stabilize the soil (soil aggregation). Those last 3 things are critically important as they allow water to infiltrate into the soil instead of running off. Once SOM reaches a point where it no longer breaks down and is stable in the soil, it becomes humus. Essentially that organic matter is carbon and is now stored in the ground. That’s carbon sequestration and why healthy soils are usually a dark brown to black in color. According to a UC Davis study, it is the best long term way to store carbon, contrary to the popular belief that planting trees is the best way. When wildfires come, trees burn releasing carbon. The carbon in the soil is untouched, that is until man puts a plow or other tillage equipment in the ground and exposes it to air. And while the study of soil is somewhat mudded (pun intended), the 5 principles of soil health have been shown to provide quantifiable benefits.

The first principle of soil health is to keep armor on the soil. That armor is living or dead plant material. Think of it as the skin on your body. It helps to regulate temperature which allows for a more hospitable place for life to exist. In addition, it slows down water as it hits the ground which allows the water to enter the soil and reduce the crusting on the soil surface. The second principle of soil health is to minimize soil disturbance. That doesn’t mean eliminate it because at the core of the soil health principles, it is my belief that we are trying to replicate nature. Nowhere in nature is a place completely static. And while I do see a place for the plow and other tillage equipment, in my opinion it has been one of the most destructive technologies that man has ever invented due to its overuse. When used judiciously, it can have benefits. As I traveled back and forth across the state over the years, I would see large dust clouds coming from field equipment plowing fields. Not only does that pose environmental and health concerns, but that’s the farmers ability to grow a crop floating away. Plant diversity is the third soil health principle. Having a diverse species mix allows for feeding soil life. I would say the majority of the population would agree that a carrot is a healthy food item. But if all you ate was carrots, that wouldn’t be healthy. The same thing goes for the soil. The diversity in plants also attracts a diversity in animal species, both harmful and helpful. Having the diverse plants also allows for making the most of from the available sunlight through photosynthesis. Different shape leaves and plant structures allow for this to happen. The fourth principle is having a live plant root in the soil. Just like how plant diversity feeds the soil different types of food, having a living roots in the soil gives a continuous supply of food for the soil. Last, and my favorite part of 5 soil health principles, is integrating livestock. Even though I received a degree in Horticulture, it wasn’t until I had my first taste with the livestock gateway drug, aka chickens, that I developed an interest in farm animals. Plants and animals evolved together, and it’s the ability of animals to cycle nutrients that makes them so important to the soil. How we manage them also plays a vital role in whether or not the livestock help or hurt soil health. Those of us involved in raising livestock have to understand that we are continuously being scrutinized by government, various activists, and the general public in what we do. The better we manage the land and livestock, the less we open ourselves up from unwarranted criticisms. As an added benefit, the attention we devote to our management leads to increased productivity which pays off in higher profitability. Alex Case Cohen, Natural Resource/Farm Planner with Stevens County Conservation District, sums up the importance of the 5 principles of soil health best by saying “The more we simulate nature, the better our soil will be. If we incorporate perennial and annual plants, minimize disturbance, and re-introduce livestock in a pattern reminiscent of pre-historic grazing, then improved soil health is absolutely attainable”.

Taking soil samples and sending them to a lab for analysis is going to be the ideal way to see how we are doing at taking care of our soil. You really should be taking a soil test before you do anything to it. But in lieu of a soil test, there are a few things we can look for. It starts with using a shovel to take a scoop of soil out of the ground in profile. If it looks dark in color and has a consistency like cottage cheese, job well done. That dark color is organic matter in the soil which is helping to form aggregation, or that cottage cheese texture. After that, look and see if you can find white branching filaments like a spider web which is mycorrhizal fungi. Mycorrhizal fungi has a symbiotic relationship with plants to increase water and nutrient absorption by the plants. (As a side note, plants can also communicate with each other via mycorrhizal fungi.) Now break up that soil and look for earthworms. Earthworms are like a keystone species for soil life. There are a few other beneficial insects you might see like springtails, pillbugs, and spiders, but it is what you can’t see unless you have a microscope that is truly amazing. Next, take a big whiff of the soil. Does it smell putrid or have a neutral to sweet almost bread like smell? The putrid smell can be an indicator that the soil is lacking oxygen. With these quick observations, an individual can make a quick assessment how their soil is doing.

I do not even attempt to consider myself an expert on soils. My formal education on the topic ended with my Agronomy 101 class. There are many much more qualified people to talk about the subject in further detail but I would like to suggest to those of you who are interested on the topic to look up Ray Archuleta, formerly of the USDA-NRCS if you don’t already know him. He has a multitude of presentations on YouTube that are extremely informative and I highly recommend them. I have spent many a late night watching his presentations, to which my wife can attest to. She probably thought I was watching something else…

Following Gregg on Facebook, Instagram, and twitter @olaainafarms or email him at gregg@olaainafarms.com

Published in Volume 12 Number 2 of the Silverado Express