Turning Trash

[digitS']

Plant wastes . . . Frost-killed stuff. What's it take to make a meaningful contribution to soil fertility?

Composting reduces the material by 40% to as much as 75%, the universities tell us. The resulting compost? Of course, the nutrients vary depending on the materials going into it. Colorado State U says: "the nitrogen percentage of compost and manure products is typically only 2 to 4% . . ." I suspect that number is optimistic but CSU further points out, "With compost and composted manure, the release rate is even slower, 5 to 25% the first year . . . the amount of actual nitrogen release to support crop growth is very small." (link)

So, I apply organic fertilizer but still make complete use of plant wastes in the gardens. I've made and used compost in many ways. Most recently, I have simply dug out beds to an 8" to 10" depth and buried "compostables."

With all the frost-killed plants this month, that task took some time but is now finished in the "little veggie garden." All of the dahlias came out of the dahlia garden to add to what was available from the veggies. The beds are the same size: about 100sqft each. So, how many beds of frost-killed plants can I get in 1 bed? About 3, sometimes 4.

-- So, 3:1 or 4:1 . . . The ground where that material comes from will have to find other sources for building organic matter and fertility. --

John Jeavons, of biointensive ag fame, says that we should put 60% of our gardens in "compost crops." (link) Wow! Fortunately for us hard-working gardeners, he doesn't quite mean just growing things for the compost pile. Sweet corn can be a "compost crop" since most of the material can be returned to the soil. In fact, Jeavons wants us to grow, at least, some things just to feed the soil.

Okay, that's all well and good - and, I think it is about right. However, good gardening multiplied by OVER double each year to not just feed the family but the soil is some work!

Steve

 

[nittygrittydirtdigger]

After a week of neglect, our veggie garden space was completely covered in white Dutch clover and sorrel. It used to be a horse pasture before we tilled it for the first time this past spring. Well, there was no way we could get all that stuff cleared, so we just mowed around the veggie plants with our small mulching mower and left the cut clover and sorrel to lay on the soil and decompose. I'm hoping we will reap the rewards of this little experiment next year with healthier soil. The immediate benefits were that our garden looked really pretty, and the honey bees and bumble bees, etc were dizzy with pleasure over the clover lunch buffet. Also, we didn't have to water as much in this dry SE Washington climate.

We liked the look of the cut clover so much that we broadcast clover seeds on the side of the house that the former owner used as a gravel parking lot for his orchard workers. It's coming along, but this late in the year, it won't flower. But there's always next year!

 

[journey11]

I like the added value you get from plants like winter wheat, whose roots can potentially go down nearly 5 feet into the soil. In addition to the humus it adds when tilled under, it also brings up trace minerals from below.

Most of my garden food plants though, depending on the likelihood of furthering a disease problem, I may or may not compost or till them in. Anything seedy or diseased gets burned.

Like Nitty's mown clover, I'd like to look further into what plants to use for living mulch. I've read a little about it, but really don't know what to plant that wouldn't take over. Or the timing on it, perhaps, if that's how they do it.

 

[NwMtGardener]

Well, this makes me feel better about that GINORMOUS zucchini plant that took over half my garden and never produced any zucchini! I was very satisfied to toss it on the compost pile.

 

[digitS']

Well, of course you should, Heather!

I feel neither guilty nor a failure for composting something. What I feel like is that I'm feeding organisms that will feed my plants. It isn't as if I'm planning on NOT growing something on that ground again!

That white clover can be of real benefit to garden plants. I've never grown a "living mulch" but we know that there is not all that many ways to extract some of the huge amount of nitrogen that is in the air and . . . feed it to the garden. Legumes can do it and I try to take special care of green material.

Ever wonder how a "green" becomes a "brown" - composting-wise? Chlorophyll is mostly nitrogen or, a lot of it is. If plant material is allowed to dry in kind of an uncontrolled way - the nitrogen is just lost into the air. The "green" is lost and so is the N.

Water captures nitrogen. "Rainfall adds about 10 pounds of nitrogen to the soil per acre per year." (link) I suppose that Colorado State U is taking snow into account when they say that. I have really wondered how gardens in the South can maintain soil fertility with such rapid & continual decomposition going on in the soil. Auburn U says that 18 pounds of N are delivered to the soil by rain along Alabama's Gulf coast. These numbers aren't nearly enuf for most crops but they certainly account for something.

Steve

 

[hoodat]

I'm of the opinion that the real benefits of compost are in the soil microrganisms it supports. I seldom let compost get to the fully broken down stage. I get better results when I turn it under well decayed but still coarse. If you let it decay all they way a lot of the food microrganisms consume has already been consumed by the microoraganisms in the compost pile itself.

 

[digitS']

Hoodat, one of the reasons I've used so much soil in my compost making the last 20 years is because I worry that I'm losing nutrients into the air, otherwise.

Once again, local conditions may make all the difference: my gardens have very rocky soil. I imagine, at least, that there is a lot of air in the soil after it has been loosened, just because of all the gravel.

Once the compostables are buried, I can come back on the 1st of April and poke around in that bed. If it was green in October, some of it anyway, will be green right thru the winter! When I planted the seed potatoes, they went in with a post hole digger. I didn't need to disturb the compostables below them but I dug right down to that level when I harvested the spuds. There was still a fair amount of fibrous material in early August!

These beds that were just dug out - essentially, I can't find anything of the decaying plants! This process of decay has taken 12 months -here- where the soil freezes every winter. I think I might be almost in a desperation mode trying to get organic material into the ground if I gardened somewhere the conditions were different - where the ground doesn't freeze and there is a lot of moisture and warmth in and out of the growing season.

With this rocky soil, I really have problems with maintaining soil moisture. There is an important, additional value to organic matter - retaining moisture.

Steve

 

[hoodat]

I was never able to keep much organic matter in my soil when I lived in Oklahoma. That hot humid weather just gobbled in up. The woods there only had an inch or so of litter on the ground and even dead limbs would disappear in a year or so.

 

[baymule]

I have really wondered how gardens in the South can maintain soil fertility with such rapid & continual decomposition going on in the soil.

Steve

I can't speak for everyone else, but I have chickens and horses and I am a super-duper-pooper-scooper!