Two Letters Re: Advice on Sawdust and Other Barn Waste as Fertilizers

Jim:
Something to very careful with when composting sawdust is to be absolutely sure you do not have any sawdust from pressure treated wood. There is a myriad of nasty chemicals in this wood that will destroy your compost heap. Sawdust should not be added directly to your garden because it absorbs and holds moisture and other nutrients. Wood ashes are fine, but only add 1 or 2% Phosphorus and 3 to 7% of potassium. Wood Ashes have an alkaline effect on your soil. I put eggs shells and coffee grounds and wood ashes directly into the garden all winter on top of the snow so as it melts in the spring it helps incorporate into the soil. Before I roto-till in April, any compost I have accumulated since the previous April goes in and then I get a load of Cow /Horse manure from a neighbor. Then I roto-till and let it set until mid to late May when I plant. One last thing: Never add Chicken manure directly to the growing garden unless it has “matured” for about a month or more. It is very high in nitrogen and tends to burn plants. – Carl In Wisconsin.

 

Dear Jim and Family,
I have a comment on the sawdust in soil issue: Sawdust absorbs between 12 and 32 times as much nitrogen as soil which does not contain it. The nitrogen helps it decay but the downside is that it makes the soil infertile. If someone tries to sell you “topsoil” and you can ID sawdust in it, you’ve just met an enemy who trying to pull a fast one on you, and with TEOTWAWKI looming, it could doom your whole family. The only solution to sawdust contamination in your soil is to dump a lot of nitrogen into your soil and let it fallow a year or two to convert all the sawdust into useful nutrients. Covering it in plastic sheeting and doing ammonia gas injection isn’t a bad idea, as that will speed it along. Pay an expert for that. Its dangerous and explosive (Remember The Mosquito Coast? That was an Ammonia gas explosion). Then retest your soil with a kit from the farm supply store and wait for your balance to settle down. Then you can get back to building up the humic and folic acid values again (planting and harvesting crops). It’s very irritating and I keep running into people who pull this particular fast one on the unsuspecting. Don’t let them dump that ac**p on your land, and don’t let them BS you into thinking its “good fer ya soil”. It’s not.

However, if the soil contains rice hulls, you’ve got a winner. Turns out rice hulls decay very slowly and don’t absorb nitrogen but do wonders for your soil aeration, which lets roots breathe better and improves your plant health and fertility. Rice hulls are a good thing. Really good quality compost and potting soil has this. Perlite is much more common (tiny white volcanic glass beads) and does a similar task through not quite as well as rice hulls.

If your topsoil is full of clay, you’ll need to add a lot more fertilizer as clay absorbs it into its crystal structure ([under a microscope] clay looks like a xylophone when it swells and shrinks depending on water content). The upshot of that is the nutrients act on your soil and plants for years afterwards so you can get your money’s worth out of it. If you have too much clay in your soil, till in gypsum as it causes an important chemical/structural change. The clay reacts with gypsum and turns into small pellets which allows better aeration, drainage, and nutrient absorption. Its important to remember: Do not walk on wet clay soil. Make paths with boards around the beds. Don’t compact the soil or your plants will die.

Its not too late to take a soils and horticulture or gardening class at your local community college, or look into books like “Gardening When It Counts”, written by the greener side of the survival community.

One other important thing: if you use well water in volcanic areas, test it for boron or borate. Boron kills plants. Kills them really well. Its mostly harmless to humans, but to plants it’s like their kryptonite, even worse than salt. Apparently using borax soap powder was a common prank for killing lawns in the 50’s, though I’m not old enough to verify that one.

If your soil does get contaminated for some reason, you may need to either plant special crops to remove the toxins, or use a special chemical poison which destroys its fertility but kills everything (even nasty nematodes and soil parasites), or flood the soil for a few weeks to leach out the salts and then drain it off (method for removing sodium salt, potassium salt, selenium or borates from soil). You’ll have to start from scratch with all but the plant method, rebuilding your soil fertility from ground zero takes years, most of the time, unless you’ve got a lot of chemical additives and a working tractor. If you want to do that, consult an expert (I’m just educated, not practically employed in that field), get a quote, and hire another expert to inspect the work.

And if you get insect problems, use sulphur based insecticides. Unless you’re personally allergic to sulphur compounds they are the best bet for your soil. Plants tolerate sulphur well, and for some its an essential nutrient. It bonds to clay well and keeps out of the way after use so its win-win, for all but the allergic people.

Soils maps are easy to get from the federal government, as well as USGS, and most counties keep stocks of these maps though I’ve never felt the need to seek one out. I will when I someday buy a house so I know what I’m dealing with. Most government soils maps were made in the 40’s and usually detail potential uses, indicating fish farms for poorly drained clay soils and suggested crops for specific soil types known to be naturally suited to them. Soil Survey Maps are a very good tool for retreat property hunting.

Incidentally, for desert soils, with irrigation and the right temperature range, will grow nearly anything. They are the most fertile soil type. You just have to avoid the borates and salt flats and washes (those aren’t soils, just alluvium).Sincerely, – InyoKern