Plant Power: Phytoremediation (Arsenic in soil, Part III)

Chinese brake fern (Pteris vittata L.) Source: Brake fern remediation

Today I get to write about one of my absolute favorite gardening topics, and for once I’m not being ironic. Phytoremediation isn’t going to make it onto most people’s gardening hit lists, and it’s not a fad that’s going to take the nation’s gardens by storm the way a new rose or hellebore might. But for me it’s proof positive of the extraordinary power of plants; it’s hope in a polluted world; it’s a spot of green in the brownfields of industry; it’s good sense in the midst of madness.

Readers’ Questions: Arsenic from pressure-treated wood, Part II

Welcome back, everyone, and in case you just tuned in, we’re talking with Jen about her vegetable garden and the unpleasant possibility that she may be growing toxic vegetables and feeding them to her family.

Unfortunately, the best place for the garden turned out to be right by an old telephone pole, which was probably treated with the wood-preservative copper chromate arsenate (CCA), and we all know what that means: it means that arsenic (along with smaller quantities of copper and chrome) could be leaching from the pole into the soil, where it would get taken up by vegetables. Which are eaten by her children. That’s pretty scary.

Compost, trucking, and other garbage

(Scroll to the bottom for today's bit on Black History Month.)

I find myself today at TruckFlix.com, a website for truck drivers. Interesting. Of course, it is compost that has led me here, albeit via a circuitous route. Here’s a sort of overview of the process: Compost, yard-waste, garbage, landfills, municipal solid waste, cities, New York City.

Put it all together and you get the question, What does New York City do with its garbage?

The answer is that it exports it by truck and rail to Ohio, Pennsylvania, North Carolina, New Jersey, and Virginia, besides sending a fair amount upstate.

Something I’ve learned while digging through the garbage recently: nothing is straightforward, and some of the stories are so ludicrous, so intricate and unlikely, that it’s hard to decide whether to laugh or cry. Toronto, for instance, has been sued by no fewer than three First Peoples (the Oneida, the Chippewa, and the Munsee) over its newly purchased Green Lane Landfill site. And that’s just the tip of that particular garbage pile.

Acidic Oceans? Keep Gardening!

(Scroll to the bottom for today's featured black artist, politician, or gardener, all in honor of Black History Month.)

I didn’t want to ruin anyone’s weekend, so I saved this one, but on Friday the NY Times reported that carbon dioxide is making the oceans so acidic that shellfish, coral reefs, and the balance of life in the ocean in general is threatened. This from a panel of a hundred and fifty-five (155) scientists from twenty-six (26) countries.

The carbon dioxide, of course, comes primarily from burning fossil fuels, and the acid comes from what happens to that CO2 when it dissolves in the ocean: it becomes carbolic acid, a.k.a. phenol, a poison so potent and so easy to produce that the Nazis used it in their extermination programs.

The world’s oceans serve as a wonderful carbon sink, removing a quarter to a third of the human-produced carbon dioxide from the atmosphere, but apparently even they have a limit.

Moral: KEEP THOSE GARDENS GOING, and compost like a maniac. Photosynthesis and soil are the other two great carbon sinks besides the oceans, so the more green things we can grow, the better. Organic matter (compost, in case you didn’t get it) also sequesters (stores) carbon in the soil. The best, as in longest-term, form for these purposes is humus, the enormously complex organic (as in, containing carbon) molecules that help stabilize soil, improve water retention, and perform dozens of other things that are good for your garden. They last for hundreds of years, so the carbon they contain is locked up for a long time. Oh, and yes, composting does produce humus!

Original article:
Rising Acidity Is Threatening Food Web of Oceans, Science Panel Says
By CORNELIA DEAN
Published: January 30, 2009

___________________________________

Oscar Micheaux

African-American of the Day: Drawn at random from Molefi Kete Asante’s list of 100 Greatest African Americans. (Asante, a prolific professor of African-American studies, started the first PhD program in that field at Temple University in1987.) I downloaded the list from the Wikipedia article on it, checked off the 40 or so I know (gulp) and am curious to see who some of the others are. I don’t know much about his list—it’s also the basis of a book by the same name—but what the heck.

Oscar Micheaux, (1884-1951) turns out to be one of the most—if not the most—prolific film makers of the silent era, producing and directing forty-four full-length films over the thirty years ending in 1948. A controversial figure, he focused on race issues in his films, even taking on the racism in D.W. Griffith’s The Birth of a Nation. He was the first black filmmaker whose work was shown in mainstream (i.e., “white”) theaters, and he gave the great actor and basso profundo (the lowest of all singing parts) Paul Robeson his first film part, in his 1924 Body and Soul.

Compost vs. Arsenic: And the winner is--compost!

Several posts back I mentioned in passing that compost can help fix arsenic in soil, and it seems reasonable to explain what the hell I was on about there. To "fix" arsenic is get it to bond with other, stable molecules so that it can neither leach from the soil into the water supply, nor migrate into your vegetables, and thence into you.

I got onto this originally because the news articles about the great Tennessee coal ash spill of '08 kept mentioning arsenic. Arsenic, I learned, occurs in several different forms, but the one that turns up most commonly in coal ash is arsenate(V), the same form that leaches into soil from telephone poles and fences treated with copper chromate arsenate (CCA).

And yes, at least one recent study conducted at the University of Florida found that when carrots and lettuce are grown in soil that's contaminated by CCA, both vegetables absorbed less arsenic when the soil received plentiful treatments of compost. 

Er--coal ash as a soil amendment?

I always knew the Brits were crazy.

Given the justifiable panic over the Tennessee fly ash spill here in the States, it’s almost impossible to believe that people might put anything remotely resembling coal by-products in their gardens on purpose, but they do.

Sounds nuts, I know, but experiments have been ongoing in experiments have been conducted in India, Australia, China, and the United States, Poland, Thailand, and who knows, maybe the North Pole, growing vegetables (or in China, trees) in soil amended with bottom ash. Since ash is almost always quite alkaline (pH>9), this only makes sense in soils that have low pHs, but in those it can raise pH, improve water retention, improve mineralization, and increase nutrient availability. And at normal agricultural application rates (20 tons or more (!) or so on each hectare, which is about 2.5 acres) virtually all of experiments I’ve looked at show that these unlikely amendments are not accumulating at dangerous levels in plants.

Coal ash in the garden?

Coal ash has been coming at me from all directions; by an odd coincidence, a recent commenter on last summer’s wood ash in the garden posts wrote about coal ash, even as I worked on the post about the great ash spill at the Tennessee power plant.

Jacqueline had been putting her ashes from wood and solid fuel on her vegetable garden for a couple of years, though she did the responsible person’s internet search first, finding only sites touting the benefits of ashes in general. Then, just a week or two ago, a response to a letter in the Guardian cited the smokeless fuel folks as saying that these ashes should under no circumstances be put in gardens.

Gulp. So—how bad is this bad news?

For arsenic-free water, pull up your compost socks.

I realize that this post-title sounds as if I'd lost both my remaining marbles, or else as though I were trying to imitate the inimitable off-the-wall titles of the great Blogger from Blackpitts, James A-S himself. But no. As you will see.

Let us begin with the subject of spreading compost. Easy, right? All you need is a wheelbarrow and a shovel. Well. Check out the photo below.

Source: Compost: Completing the Cycle
Texas Commission on Environmental Quality (TECQ), 20

That, folks, is how they do it in Texas. Apparently, when they go for compost there, they do it big-time. (Why am I not surprised?)

Compost blankets like this one reduce runoff, making reseeding disturbed soil far quicker, more successful, and therefore economical than it is when using what are disparagingly referred to as "traditional methods." But that's not really the point here. The point is the machinery, which I'll return to in a minute.

The Wrinkled American: Tumble Dryer Addiction

So while we’re on the subject, has anyone checked out the tumble-dryer posts over at Bean Sprouts? Read through the comments on the last two, “Tumble Dryer” and “Tumble Dryer Again,” and you’ll meet scads of people who don’t own dryers. As I said in a comment, my bet is that most of them are British, not American or Canadian. Over here, if you live in a house it’s got a dryer, and if you live in an apartment, you probably wash AND dry your clothes at a laundromat.*

Sometime this summer I discovered that #1 son almost never uses a dryer. Inspired, I’ve been trying to wean myself from dependence on the thing, as it's a veritable energy-sink, and have dried more and more clothes on racks. (There are no radiators in this house, just hot air vents, so what I’m coming to see as the British Dryer Alternative (BDA) isn’t really an option.)

News Flash: Pine Beetles devastating US Forests

New York Times, Nov. 17, 2008--Montana campground.

Clint Kyhl, a Forest Service employee working out of Laramie, Wyoming directs an “incident management team” that focuses on managing fire threat in dead forests. Dead forests? Yes. Because more and more, up and down the Rockies, that’s what we’ve got: dead forests.

I don’t need a newspaper to show me this; I can see it when I look at the foothills of the Hyalite Mountains just south of Bozeman, and when I go skiing in the Bridgers to the north.