Search This Blog

Thursday, August 3, 2017

Soil Building 101

I have honestly never had a book spur me to so much action.  For years I’ve been saying I gotta do something about my soil fertility, I gotta do something about my soil fertility, but I haven’t been able to get my arms around how to do it on the scale or speed I need to.  My soil is essentially dead.  Not completely dead, but pretty darn sick. But now I have a start and it's all because of this book and a perfect storm of information coming to the fore at roughly the same time.  I have to admit here that it's probably because I was so frustrated that I asked for Help.  And I got it. It all pretty much happened within ten days or so.

The Hidden Half of Nature: The Microbial Roots of Life and Health is a great read that deals with microbes: fungi, bacteria, and viruses, and their critical part in how life on the planet works. Starting with a backyard full of dead soil in Seattle, David R. Montgomery and Anne Biklé are drawn into the world of microbes when they notice that the mulch they’ve been applying to their yard keeps disappearing and yet the almost gray dirt is being replaced by dark, friable soil that is making their yard the envy of the neighborhood. When Anne has a bout with cancer, they are drawn into the fascinating world of the microbiome that is the human body*.  We are nothing but a vessel for holding billions upon billions of microbiota without which we can’t digest food or fend off pathogens. Betcha didn’t know that.

In the book I learned that soil microbes act as middlemen between the soil and plant roots.  When they tell you ‘feed the soil’, what they really mean is ‘feed the microbes’.  Plants can’t take up soil minerals on their own, so their roots exude compounds that attract soil microbes. The soil microbes are attracted to the exudates and hang out very, very close to the roots (so close they create what is called the rhizosphere) and sip on exudates and eat soil minerals and dead things. Then they poop and the roots absorb what’s in their poop.  The plants can’t live without the microbes because they can’t digest what’s in the soil without them.  Plants also count on soil microbes to help them ward off disease and even in some instances, insect attacks. They talk to each other via chemical pathways.

I also learned that fertilizing your soil with chemical fertilizers will kill the soil over time, because it removes the dependence on soil microbes, and in some cases, just plain poisons the microbes. Plants manage by the sheer amount of minerals and substances that get dumped into the soil, but the upshot is that as the microbes die off, the plants require more and more fertilizer until the point that the soil is dead.  And once the soil is really dead, nothing will grow in it. I’m certain that’s what happened to our soil because when we moved in here there were a half dozen or so sacks of the same kind of fertilizer stacked up in the garage.  The previous owner, Mr. Hunt, came late to the organic growing party, but that was well after he’d killed his soil.  I didn’t know that I haven’t been doing the soil any more favors by adding organic rock phosphate and cotton meal and other types of organic fertilizers.  The only way to improve soil is to add organic matter. It truly is. 

However, it’s not the only thing you can do if you can’t wait for nature to take her sweet time turning it into good soil. David and Anne mentioned in their book that in addition to mulch, Anne also applied ‘soil soup’.  I emailed her to find out what she used for mulch and asked if could she give me the recipe for soil soup (this was after I looked all over the internet to see if it was posted anywhere- on their website, in any talks or seminars they’d given, but I couldn’t find anything).  The mulch is a combination of wood chips and leaves, and she agreed that it was kind of like composting in situ, minus the kitchen scraps.  The soil soup is a combination of vermicompost, water, molasses and kelp powder and in looking for an exact recipe and method, I’ve since discovered why this breaks down the mulch so quickly, but we’ll get to that later.

The immediate problem for me was how to get my hands on the wood chips.  Years ago I read in the Mother Earth News that they had discovered that wood made the best soil after reviewing the results of the test they ran specifically to see what makes the best soil.  And after watching the film Back To Eden, I knew that to get this soil, you needed wood chips on a large scale. Paul Gautschi gets his from arborists.  Somewhere along the line I learned that what you really want are ramial wood chips. Ramial wood chips come from the branches of deciduous trees that are no larger than two and a half inches in diameter (less than seven centimeters).  The reason for this kind of specificity is twofold. One is that you want the branches to be of a certain size to ensure that the wood itself is still full of soluble lignins; this means that they will break down quickly.  The second is that you only want wood from deciduous trees because they encourage white rot.  Evergreens, particularly conifers, encourage brown rot.  White rot is good because it encourages growth; brown rot is bad because it discourages growth.  So when I asked about wood chips from the arborists who were taking down the neighbor’s deodar cedar, they told me about is a terrific internet service that matches arborists with folks who need wood chips.  Specifically free wood chips. You can’t specify what species of wood you want your chips to be from, but you can specify what wood species you are not willing to take.  They’re quick to caution you that because these chips are coming straight from a job, there will be needles or leaves or both mixed in, depending on what you’ve specified.  A mix of wood chips and leaves is ideal.  You can also tell them if you’re willing to take some logs off their hands, which I will probably be doing this coming fall sometime when I’m ready to spread conifer chips over my pathways (remember: conifers encourage brown rot which discourages growth- perfect for a pathway).  To increase your chances of getting a drop, you can agree to let them charge you twenty dollars or more; this takes away the fee that the arborists would have had to pay to dump their chips elsewhere.  I decided to opt for this because I was being picky about the kind of chips I wanted.  Two really important things you should know about is that you will in all likelihood NOT get a notification when they are coming; they will come when it’s convenient and leave the chips where you specified in your instructions.  In our case, we were lucky enough to follow the guy into our neighborhood after coming back from grocery shopping and I knew right away those were my chips!  We just had to beat him in or at least be right behind him because my instructions were to dump them in the driveway.  I had Steve stop the car so that I go get out and run up to the driver’s window so I could ask if he could wait a minute while my husband put the car away.  I don’t know if I was more excited to get the car in the garage before he’d dumped the load or if I was just excited because I was getting a load!  

The other important thing you should know is that once you get a drop, you fall off their system, so if you need more, you have to sign back on, which is a really good feature. No more surprises.  But for free or nearly free wood chips, this service can’t be beat. As far as I’m concerned, my wood chip sourcing problem is solved.

The load they dropped was from a giant ash tree a few blocks over, which was perfect. There are probably some chips in there from branches larger than an inch and a half, but I’m not really concerned about it because the soil soup I am making will help them break down quickly.  

Soil soup is made by growing the number of microbes in a quart of vermicompost in five gallons of aerated water, with the addition of an ounce of organic, unsulphured, blackstrap molasses and an ounce of kelp meal or fish emulsion.  Here is a picture of the batch I started yesterday.  Before starting, I drilled a one-inch hole near the bottom of the bucket and installed a bottling spigot, which I also got from Amazon. If you're going to do this, do yourself a favor and drill the hole using a one-inch hole saw- it does a much better and neater job of it than a one inch spade bit.  Trust me on this.  Then I ran the air through the water for a few hours to blow off the chlorine in the water. It also makes sure there is plenty of air in the water before you start. I also lined the bucket with a five gallon paint strainer, which will keep the large pieces of vermicompost from clogging the spigot.

Aeration is important for making soil soup because it keeps the microbes from using up all the oxygen in the water and dying off, which would defeat the purpose. You want to add live microbes to the soil and wood chips.  I purchased an inexpensive aquarium kit off Amazon which contained the air pump, tubing, and two aeration stones. The addition of molasses to the mixture encourages the growth of soil bacteria and the addition of the protein-based kelp powder or fish emulsion encourages the growth of soil fungi. It’s easy to be tempted to focus on the fungi because they do the heavy lifting in wood deconstruction but you need the bacteria as well because they have a job to do, too.  Leave the concoction to aerate and grow for three days and then water it into your wood chips and soil.  I didn’t see anywhere how often to do this but I hope to be able to get through the whole yard in a three week period and then start over and keep doing that until the rainy season sets in. So maybe two or three times over.  

If I’m good and stay on top of this, I expect that with just the wood chips and soil soup alone it will take a good four or five years to build the soil, but I’m not expecting that this method will be the only thing I do.  Since the wood chips and leaves will be composted in situ, I’m considering making a worm composter and keeping it under the kitchen sink.  I’ve never been crazy about having to take the compost out to the compost pile in the winter time and this would be a good way to avoid that. I would also be growing my own source of vermicompost which is probably the best reason for doing it.  The other soil input that I’m counting on is rabbit poop, which I’ll probably compost along with the muckings from the chickens.  However, rabbit poop is one chicken I’m not going to count until it’s hatched. The nearly free wood chips and soil soup will be the major constituent of my soil building. 

Now that I have it underway I am quite frankly, relieved.

*Did you know that there are more microbial cells in your body than there are cells that actually make up your body? And that the human gut actually talks to the brain via the vagus nerve? And that the microbiota in your gut are more responsible for your mood and personality than your brain is?  If you want to see something really fascinating, watch The Gut on Amazon Prime.


Amanda said...

i was reading and thinking, "omg, i have to tell her about chipdrop!" my friend coded the original app and i've been using it for a few years. i don't use it in my vegetable beds, so I'm actually fine with pine, I kind of love the smell of it. got another drop last month. it does fine for mulch and actually broke down really well. you will ALWAYS get your drop within 24 hours, but generally you do get an email that its about to happen, like 3 minutes before it really does.

Leigh said...

Paula, what an excellent post. Dan and I have been eyeing a PTO chipper attachment for our tractor, but it's pricey. I didn't know about chipdrop - thank you! After we watched Back To Eden I looked around for wood chips but trimming companies had taken to selling them anywhere from $20 to $25 a front end loader bucket scoop. That would be pricey too! I'd not heard of the soil soup, but was just telling Dan I want to have another go with compost worms. Again great post. Lots of information that Dan and I have been trying to put together ourselves.

Paula said...

Awesome- I'm glad this post was helpful. It was meant to be!