Fill dirt and cover crop vs wood chippings

Hi friends! I've recently moved into a new home and just finished reading Gaia's Garden, and I'm raring to go. However, there's still a lot I don't know.

Most of my land is already heavily wooded, so I'm working on thinning out the woods enough that I can plant some things below. I have an area where I've already slashed down all the thorns and tiny saplings, and have taken out two 6-8 inch trees.  The ground is very uneven and rocky, so my plan at this point had been to find some fill dirt and then put down a spring cover crop and slash it down in a few weeks.  However, I don't have a dump truck and am having some trouble getting the fill dirt. My neighbor owns a landscaping company and has offered me all the free wood chippings I want.

Should I keep looking for fill dirt? If I get it, should I top it with the wood chippings or the green manure? Or both?  I'm planning to put blackberry and raspberry bushes for now, though I eventually want to expand it so that they have guilds to support them.

Or is there something I just don't even know about that I should be doing instead?

Thanks!

Hi Ruth, welcome to Permies.

In the world of "dirts" and companies that sell soils, just be mindful that fill dirt and topsoil are two different things. What they call fill dirt is usually subsoil. That being said, there are many unknowns with bringing in topsoil from another location. Did it come from a new commercial construction site next to a highway that's had 70 years of automobile exhaust exposure? Did it come from a construction site next-door to an industrial park? There's usually no way in knowing where that topsoil came from. If it were me, I would refrain from importing soil, and work with the native soil you have. I recommend taking up the offer from your neighbor for all the wood chips you want. The results will not be instant, but with time, the decomposition of those wood chips and the boost in microbial activity they will provide to the native soil will be far superior to bringing in topsoil.

Hi Ruth. Welcome to Permies.

I think that to be of any use to you, we need a little more information. Where are you located, and what plant hardiness zone?

Also, what is the overall layout of your land? You mentioned rocky and uneven, but that could mean a lot of things. What is the predominant rock type?

It also depends on what you want to do with the land. If you want a food forest, dominated by woody perennials, you want a soil biology that is more fungal than bacterial, although you will still want both.

I would say that piling on the wood chips is a fine idea, especially if you inoculate them with a compost extract.

If you don't yet know about them, Bryant Redhawk has some awesome threads about soil science that cover the topic. It essentially entails taking sources of beneficial soil microbes and dropping them into a bucket or barrel of water, ideally with a bubbler or some other method of oxygenation (I haven't discussed it with Redhawk yet, but I think that, if I were working on a 5 gallon bucket level, I would just pour the extract from bucket to bucket twice daily, or more, straining through a metal strainer to separate the extract into droplets, better oxygenating it).

I could easily see you mulching with wood chips, inoculating with a compost extract, and turning all those woodchips into soil. You could then use much less imported soil or fill by amending individual plantings. Meanwhile, the compost extract applications would slowly make soil out of wood chips, and any fill that came your way could just go on top, perhaps topped with more wood chips.

The fill, incidentally, is likely to be lifeless dirt, should you be able to get it. It is really important to get life into the soil, by putting into it what the organisms need for food, and by structuring the soon-to-be-soil advantageously. That means an addition of organic matter, as well as amending the soil for whatever it lacks. You would do really well to have a soil test done on any fill you bring on to your property, not just for safety's sake, but also so that you know how it needs to be amended.

It is crucial to get living plants into the earth wherever possible. Be careful in the clearing of the land. Some trees, sugar maples, for instance, engage in an activity called hydraulic lift, wherein trees draw water from their deepest roots closer to the surface, which also makes it available for other plants, trees, and organisms.

When clearing, make sure you identify any nitrogen fixing perennials, especially in a temperate climate where they lose their leaves seasonally. Some also coppice nicely, meaning that you can cut them back and they will regrow from the stump, using them to make buried wood beds, raised or in depressions (hugelkultur, if you're not familiar with it), or for renewable firewood.

I am not saying not to clear trees, but make sure you're observing, and make sure you know what you're clearing, so that you can either dessicate what you remove, should it root from cuttings, bury it in where you want soil should it be high in nitrogen, or just know that it is safe to use as something as innocuous as on-contour sediment traps (branches and rocks and stuff laid out across slopes to slow water and trap sediment, eventually creating something like terraces).

Also, plants feed eachother through fungal networks, releasing root exudates, signaling what they need, and taking the exudates of other plants, albeit indirectly, through the soil food web.

My explanation is simplistic, but the easy takeaway from it is that life nurtures life, in most cases. Unless the soil food web is weakened, broken, or unless the population of plants require too much of the same thing for the area to provide, or in the case of allelopathy, the more life is in the soil, the easier it is to keep life in the soil, and healthy.

So get down everything you can. If it's just wood chips, then wood chips will do. There are things, like the compost extracts, that you can do to speed up the process of soil-making, but just getting mulch on the land will mean sheltering the barest ground, catching rain and wind-borne sediment, trapping moisture where the soil life that's already around, probably hiding in the oases of the root zones of the living plants in place, can make use of it to turn those wood chips and the dirt and grit into soil. Sediment traps, again, only speed up the rate of sediment deposition and increase water infiltration.

Let us know how it goes. Please keep us posted, and good luck.

-CK

Thanks so much for your help, folks!

I live in Virginia,  zone 7a.  

I honestly have no idea what the predominant rock type is.  Can I say "big?"

Do you have a recommended compost extract?

I am hoping to move toward a food forest, though I'd like to do so without too much disruption of the forest that's already there, so I'm planning to leave most of the trees in place and work on changing what's under them- raspberries and blackberries instead of the wild, mostly-thorn versions, to start.

If I put down the wood chips directly on top of the existing soil, will the cover crop seed be able to take root through those? Or would the green manure need to wait a few seasons for the wood to compost?

Thanks so much! I appreciate your help and your not laughing at my lack of knowledge.

Ruth, if you go to the following site and watch the free film Back to Eden Garden, it will answer many, if not all of your questions.  There are quite a few people here that are implementing that type of gardening, and some of us (me) really envy people that can get all the free wood chips they need.

Back to Eden film

Ruth

That stump in the photo looks like a Wild Black Cherry to me. That's the furniture lumber/ firewood cherry. I assume you've already cut it up in short lengths. If so use it for firewood or give it to someone who'll appreciate it.

Thank you, Todd! I will definitely set aside time for that!

Thanks, John! Good to know. We will most likely be using it for firewood. I'll have to keep an eye out for any others- I do actually make furniture, I just tend to buy Home Depot lumber.