Dave: Biomass Problems

Hello Dave!!

I am about 50 or so pages from the end of the Massive Forest Gardening book. ThankyouThankyouThankyou!

It has been a long trek into this book but well worth the effort. I'm just browsing for now and hope to re-read and actually put in practice the designing process laid out in the book.

I guess the part about mulching sticks in my mind the most, and not only because I just read it last night.

My sources of mulch currently are:
-Kitchen scraps from 2-3 houses (friends, family)
-Purchased straw (expensive, but helps)
-Clippings from my 3 of my friend's no-chem yards.
-Will have access starting this year to about 1000 square meters no-chem grass, grown high and dried, re-cut in the fall about mid height.
-Random visits to the cow farm for less than a truckload of manure. Slightly dubious about what's in that.

However, this doesn't seem like it's nearly enough. We currently have about 500 meters and 1 hectare (2.4 acres) on which we are growing veggies (on the first) but moving into shrub and tree crops (asap!).

On the other hand, my goals are to grow some plants for biomass onsite and use rooted plants to grow biomass in the soil.

Obviously these strategies are not mutually exclusive, but my problems are these:

-Dubious nature of nearly all off-site mulch material. I could probably go to the town dump and pick up truckloads, but I have no idea of what kinds of junk is in it. It usually ranges from seen plastic to unseen chems. Not stuff I really want to put near my food. But it is really limiting.

-Difficulty of finding biomass plants that are not invasive or root crops that really are good at putting biomass into the soil. I've used daikons but the soil seems too hard to really get a good root down (I'm in hard clay btw, so it's a chicken-egg problem with soil/root biomass) and any other plant roots just get eaten up really quickly by the soil. I leave almost all weeds except invasive grass as of now and I'm working on getting comfrey going on a large scale. In beds we weed heavily but leave a lot of roots and grow a lot of n-fixers and we don't take roots out.

-The fact that organic straw is impossible to find, even if I decided to take the risk because I like straw so much.

I have made many swales in the land to mitigate the summer water loss, and I've heard that helps build biomass as well. I read recently about the use of grass in building biomass, and I have some clumping grass on the site which I could move around for root growth without it getting out of hand.

We tend to not use manure overzealously because we don't know 100% what's in it and because of potential risks of overuse (acidifying soil I think).

Any ideas for how to build good soil and how to find cleaner ways to do that would be very helpful. Especially since we're moving onto a much bigger site and potentially many more biomass-needy plants.

Thanks so much,
William

One word, William, one word: nuclei.

If you try to do broadscale mulching you will absolutely kill yourselves. Just too much work. Work out where to place nuclei that you can mulch intensively, get them well under control, put your most valued and valuable crops there and get those system going first. Yes, include mulching species in those, but put a lot of crops in too--they'll build OM in the soil too. Concentrate all your biomass on those sites. In the meantime, plant coppicing willows or other species in blocks where you can cut and move the material, and plant other swathes in cover crops--grass and legumes, for example--that you can harvest mulch from also, but you are still building soil through their root systems. Then use your nuclei as nurseries as well as food production, and you can more cheaply expand your systems form there, building the biomass in the nuclei using multiple strategies and sources,and building the biomass in the other less intensive future planting zones more slowly and passively, but still building.

That's my off the top of my head response. Other things are also possible. Try to get as many diverse kinds of biomass as you can--grassy, fast decomposing as well as lighter and heavier/denser woody material. This will help diversify the soil food web. Coarse woody debris (CWD) is a critical part of woodland soils!

You can also build multilayer systems with pollarded trees, especially n-fixers at wide spacing above, harvested periodically for mulch, and crops below.

Rotational grazing also isn't a bad idea, you can build a lot of soil fast with that if you do it right. Sheep, goats, chooks . . .

OK, gotta run.

Good luck! Have fun!

d

PS: YOU ARE WELCOME! Thank you for going for it! Please share what you learn with others and spread the wealth.