WCL (Wet Chemistry Lab) sample Options

[Bill Harris]

<sigh>, in a manner of speaking, this "Mars soil is yummy" comment... snowballed?

--Bill

[Juramike]

Well....in one sense the press has picked up on a key finding, if you look at it from the eventually-there-will-be-colonists-on-Mars in a "Farmer in the Sky" point of view: the results of the basic soil of this one analysis help bring Mars down to Earth. I can imagine what kinds of crops might be grown there someday.

The Big Three, NPK (nitrogen, phosphorous, and potassium), can be adjusted by large amounts of fertilizer, and trace micronutrients can also be easily added (I use Greensand) to soil. Soil microorganisms and plants can be coaxed to live as long as there aren't any wierd yukkies (funkybad salts like arsenic) or other reservoirs of difficult reactive species.

Soil pH, while adjustable, can be a pain to deal with. Ask anyone from Texas trying to grow acid-loving rhododendrons in alkaline caliche. You can do it, but you will be adding soil amendments forever. It is a losing battle, as the background soil will continually be trying to buffer out the tiny acid patch you've installed to grow your rhodys.

So when the full results of the soil analysis are complete, (and assuming no funkybad stuff) it will be possible to picture what bags of soil amendments and other materials would be required to mix into martian soil to make it suitable for agriculture.

I have no idea why, but I find that concept both fascinating and comforting.

-Mike

[nprev]

Mike, you consistently amaze me with your ability to coin great band names..."The Funkybad Salts" would definitely kick gluteus maximi!

Thanks to Don also for the illumination. From what I gather, a pH reading alone is not enough to extrapolate detailed chemical properties and compositional details on Mars, even when compared to mass spec data. It helps, of course, but it also seems too easy to apply terrestrial analogues too freely, 'cause that's what we know. MSR is a must.

[belleraphon1]

I have no idea why, but I find that concept both fascinating and comforting.
-Mike

Mike... so do I.... "The Farmer in the Sky" has just gotten a tiny bit closer to reality .....
To me this is like being in a hard science fiction story... and so much more to come.

Craig

[Bill Harris]

Well....in one sense the press has picked up on a key finding...

It's still looking better. The last "key finding" in '76 suggested a horridly reactive superoxide mix, and you can add the "salty" sulfates at Meridiani. I'd love to put a chunk of ice into the WCL.

At home, I have to "make" soil for my flower and wildflower gardens. Except for paltry 6" of organic "A" horizon, most of my soil is a clay soil derived from the weathering of Pennsylvanian sandtones and shales, so I have to add lime, organics, sand and nutrients to the mix.

--Bill

[Juramike]

At home, I have to "make" soil for my flower and wildflower gardens. Except for paltry 6" of organic "A" horizon, most of my soil is a clay soil derived from the weathering of Pennsylvanian sandtones and shales, so I have to add lime, organics, sand and nutrients to the mix.

I hear that. I've made a garden from Piedmont gray clay (like red clay but lacking in iron). 200 million years of NOT MUCH HAPPENING leached most the nutrients out of the native soil. And it's a natural pH 4.5 as well.

But I'll bet Mars doesn't have mosquitos, ticks, Japanese beetles, squirrels, or deer.

Sign me up.

[Shaka]

Daisy World, here we come!

[edstrick]

On a world with a probable history of a magma ocean and with well differentiated crust, mantle and core, one problem I've thought of won't be a problem.

Heavy metals.

Would the heavy metal content of a chondritic soil or more specifically a carbonaceous chondrite soil cause problems?

In California, there's serpentinite and related terrains formed of up-thrust mangled bits of upper mantle. Lots of plants DO NOT like to grow there. They have decidedly special biomes growing on them. CChondrite soils would be worse!

[Bill Harris]

I don't know much about heavy-metal content of chondrites. Do you have references?

Although the Mar's convective mantle engine appears to be inactive nowadays, it may have been more active earlier. And certainly Mars has been hot and is differentiated.

--Bill

[SickNick]

Full inline quote removed - Admin.

An Undifferentiated Chondrite would have much more heavy metal content. All those Siderophile and chalcophile elements are concentrated in the core of the Earth.

Also, look at the fundamental differences of Earth and Mars. However you look at the situation, the bulk density is different, the chemical activity is different. Mars is made of different stuff then Earth is, and then it evolved different again. Never make the mistake of assuming that Mars is "like Earth"...

[dvandorn]

That's sort of a matter of degree, isn't it, Nick? In the great range of like to unlike, Mars is far more like Earth than it is, say, like Jupiter. Or Neptune. Or even Titan.

-the other Doug

[jmknapp]

Just saw this article in the Telegraph:

Martian dirt is rich in nutrients and capable of sustaining Earthly life, such as turnips and asparagus, surprised scientists announced.

But as I understood the press telecon, they've found certain trace elements, not all the nutrients necessary for growing plants (i.e., NPK). Seems like the press is being "led down the garden path" by these press conferences.

[Juramike]

Major elements and trace elements (in order), required for plant growth:

C. HOPKNS CaFe Mg B Mn CuZn ClMo

("C. Hopkins Cafe, managed by mine cousin Clomo.")

It will be really interesting to see the quantitification of trace elements detected (I assume in ppm).

And if there are heavy metals? No problem. Just plant ferns just before your martian bean crop as in this article/video.
(Bad luck that most ferns are acid-loving, but maidenhair ferns like pH 7-8)

-Mike

[antipode]

The bizarre flora of long isolated New Caledonia is a fascinating example of long term adaptation to soils rich in often nasty heavy metals and other baddies.

p

[nprev]

...cool mnemonic, Mike!

This whole spin-up is a bit unfortunate, though; expecting to be bombarded with questions from my co-workers tomorrow (been gone for the last 2 weeks attending a class). After all, plants have been grown in lunar soil, but that does not imply that life arose on the Moon, merely that terrestrial life needs certain stuff to exist & the Moon happens to have it. Big difference.