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Clear-Cut
01-14-2009, 01:35 AM
a friend of mine needs this question answered...if you are not positive please to take a guess...also an explanation for the correct answer would be great

here it is for all of you soil and plant experts

1. Which of the following elements required by plants does NOT come directly from the soil?

a. Carbon
b. nitrogen
c. magnesium
d. potassium
e. iron

Thank You and Good Luck! :drinkup:

lkc
01-14-2009, 02:00 AM
Just a guess but I am going to go with nitrogen.

greendoctor
01-14-2009, 02:02 AM
Its nitrogen, all of the other elements only exist in solid form.

44DCNF
01-14-2009, 02:14 AM
It is Carbon. A plant gets it's Carbon from the atmosphere as CO2.

Kiril
01-14-2009, 02:24 AM
Your question is too general, as all of these elements exist in the soil in one form or another. It would be more appropriate to distinguish between a mineral or organic soil, and if these elements are simply contained within the soil, or derived from the parent material.

If this is for a test, then I would say carbon, and shame on you for not knowing.

Kiril
01-14-2009, 02:35 AM
It is Carbon. A plant gets it's Carbon from the atmosphere as CO2.

Not necessarily, however that is the primary source.

topsites
01-14-2009, 03:06 AM
First off, magnesium, carbon and nitrogen can and do exist both in the soil AND the atmosphere.

Then, at least potassium bromide and potassium chloride are also found in the atmosphere, and you may not
believe this but so is iron, and just for kicks sulphur too.

So any or all of those elements may or may not come directly from the soil, it all depends what kind of
soil it is and what is in it, all or any of those can and do exist in the soil but the soil could also be depleted...

And it is possible for instance that atmospheric magnesium and soil-based magnesium are not the same element,
same with potassium and whether or not this I could not tell you, but I can not answer this question from the data given.

44DCNF
01-14-2009, 04:20 AM
I am not saying the other elements do not exist in the atmosphere, or that the plant does not take them in from there, and that is not the question. Nor is it asking which element is not in the soil. I have interpreted the question as asking which of those elements is not (maybe here it should say generally) taken up from the soil. I say that is Carbon, as it is most generally taken in from the air. As is Oxygen. Hydrogen is from water along with more oxygen. N, P, S, K, Mg, Ca are taken in from the soil. So, carbon, hydrogen, and oxygen are the elements taken in from the air and water, and the others are generally taken in from the soil.
If you don't complicate the question, the answer is easy.

Agreed, the question is vague/misleading, but that is what makes tests fun, eh?

44DCNF
01-14-2009, 05:41 AM
I missed a few words, so to clarify:
"I have interpreted the question as asking which of those elements (required by plants) is not (maybe here it should say generally) taken in from the soil by the plant.

rcreech
01-14-2009, 07:43 AM
This sounds like a question off of a pesticide test. Is that the case?

The reason I ask is...this is how our questions are here in OH!

They are somewhat tricky!

I am pretty sure of the answer but sometime it is best to use the process of elimination... so all come FROM the soil except for C.

I am very positive that it is C as all the others do come directly from the soil.

Carbon, Hydrogen and Oxygen are 3 of the 16 essential elements needed by the plant to survive but is not considered as soil nutrients.

I guess I have never put down a hydrogen or oxygen applcation...although I do think an oxygen application could be quite profitable! :laugh:

44DCNF
01-14-2009, 08:07 AM
Not necessarily, however that is the primary source.

I'm curious and all ears. From where else (source other than the air), and then through what plant part and for what purpose does a plant take in and use carbon as a required or essential element? Or is it only a beneficial element when taken in from elsewhere? What form is that carbon in, that is taken into the plant? What is left after the process and what does it do with it when finished using it? Thank you, just trying to learn here. This is news to me.

Ric
01-14-2009, 11:21 AM
Yo

While Carbon is up taken by roots and C To N ratio of the soil is important I feel this question's answer has more to do with basic plant Metabolism.

Whereas 3 CO2 + 3 H2O = C6H12O6 + O2 or Carbon dioxide plus Water is metabolized by photosynthesis to simple sugar and Oxygen which is given back to the atmosphere to help the animal to plant life cycle. Carbon is retained in the plant from the atmosphere in the form of sugar.

creech

Nickel is now reconized as an essential element so there are now 17.

Kiril
01-14-2009, 11:37 AM
I'm curious and all ears. From where else (source other than the air), and then through what plant part and for what purpose does a plant take in and use carbon as a required or essential element? Or is it only a beneficial element when taken in from elsewhere? What form is that carbon in, that is taken into the plant? What is left after the process and what does it do with it when finished using it? Thank you, just trying to learn here. This is news to me.

Couple of papers that discuss this.

http://www3.interscience.wiley.com/cgi-bin/fulltext/119513274/PDFSTART

http://jxb.oxfordjournals.org/cgi/reprint/49/329/1977.pdf

Clear-Cut
01-14-2009, 12:01 PM
my answer was Carbon, because as far as i know, the plant doesnt use carbon from the soil...all of the other elements i think are found in the soil and used by the plants as nutrients from the soil.

i narrowed it down to Nitrogen and Carbon and then i googled it and here is my proof supporting that the answer is CARBON


http://www.extension.iastate.edu/Pub...ns/EDC232B.pdf

Quote:
The nitrogen cycle is the continuous series of natural processes by which
nitrogen passes from the air to the soil, to plants, and ultimately to sustain all
animal life, and then returns back to the air or soil through decay or denitrification
(the loss of nitrogen).
saying that nitrogen is released into the air as a gas, but plants use it from the soil. then after they die and decay nitrogen is released into the air.

like i said before...nitrogen is a huge part of lawn fertilizer. the fertilizer dissolves into the soil where the grass uses it..its what makes your lawn that nice deep green color

its gotta be carbon

http://www.vtaide.com/png/carbonCycle.htm
Quote:
Carbon is an element that readily combines with other elements to make organic compounds. All life on earth is carbon-based. A lot of your body is made of carbon and some of your body carbon parts were plant parts a few months ago. Carbon, used by all living organisms, continuously circulates in the earth's ecosystem. In the atmosphere, it exists as colourless, odourless carbon dioxide gas. Plants take in carbon dioxide during photosynthesis and give out carbon dioxide during respiration.

rcreech
01-14-2009, 12:28 PM
Yo

While Carbon is up taken by roots and C To N ratio of the soil is important I feel this question's answer has more to do with basic plant Metabolism.

Whereas 3 CO2 + 3 H2O = C6H12O6 + O2 or Carbon dioxide plus Water is metabolized by photosynthesis to simple sugar and Oxygen which is given back to the atmosphere to help the animal to plant life cycle. Carbon is retained in the plant from the atmosphere in the form of sugar.

creech

Nickel is now reconized as an essential element so there are now 17.

Are you serious Ric?

Cu Zn (See you soon) method for memorizing the 16 elements....so where will the add teh Ni?

Ric
01-14-2009, 12:32 PM
Yo

While Carbon is up taken by roots and C To N ratio of the soil is important I feel this question's answer has more to do with basic plant Metabolism.

Whereas 3 CO2 + 3 H2O = C6H12O6 + O2 or Carbon dioxide plus Water is metabolized by photosynthesis to simple sugar and Oxygen which is given back to the atmosphere to help the animal to plant life cycle. Carbon is retained in the plant from the atmosphere in the form of sugar.

creech

Nickel is now reconized as an essential element so there are now 17.

Clear Cut, Hello

Is my answer Not pretty much a shorter version than the Link you supplied?????

Ric
01-14-2009, 12:40 PM
Are you serious Ric?

Cu Zn (See you soon) method for memorizing the 16 elements....so where will the add teh Ni?

rcreech

OH about 1979 Nickel was added but not all factions were ready to agree. A quick Google entitled "Nickel Essential Fertilizer Element" found this and a few more.


http://www.ces.ncsu.edu/depts/hort/nursery/cultural/cultural_docs/fertilizers-nutrition/Nutrition-fertility-substrates.pdf

Kiril
01-14-2009, 12:44 PM
The current count at this time is 18 (Brady and Weil, 2002, The Nature and Properties of Soils, 13th edition) although one could argue that 16 is still accurate depending on how you define "essential".

http://www.extension.umn.edu/distribution/horticulture/DG3338.html

44DCNF
01-14-2009, 12:58 PM
Thank you for your answers Ric and Kiril. T'was a big help. There was one other question nagging at me, but I might try to post back later if Kiril's second article doesn't answer it.

Clear-Cut
01-14-2009, 12:59 PM
Clear Cut, Hello

Is my answer Not pretty much a shorter version than the Link you supplied?????

i dont know anything about chemistry and adding elements and what not...

i was just proving my own reasons for going with Carbon...

to answer this i just used my reasoning and eliminated all of the possible answers and ended up with nitrogen and carbon, then after that i used my superb googling skills lol

Ric
01-14-2009, 01:07 PM
Kiril

Yep I see Cobalt has been added now. I am sure there will be many other trace elements discovered as out technology grows. How these newer elements function in the plant is still not completely understood, only that they are up taken.

KACYDS
01-14-2009, 01:18 PM
Nickel is now reconized as an essential element so there are now 17.

Hey Ric,

Now that Nickel is an essential element, How much is needed for each plant?

If each plant needs 5 Nickels, can I add 1 Quarter, or 2 Dimes and a Nickel?

lol:laugh::laugh::laugh: Just trying to be funny..........and I guess its not working.:dizzy:

rcreech
01-14-2009, 01:29 PM
Hey Ric,

Now that Nickel is an essential element, How much is needed for each plant?

If each plant needs 5 Nickels, can I add 1 Quarter, or 2 Dimes and a Nickel?

lol:laugh::laugh::laugh: Just trying to be funny..........and I guess its not working.:dizzy:

I like it!!!! :laugh:

KACYDS
01-14-2009, 01:38 PM
I like it!!!! :laugh:

Thanks, rcreech.

Just trying to have fun! :blob2::blob2::blob2:

Ric
01-14-2009, 01:40 PM
Hey Ric,

Now that Nickel is an essential element, How much is needed for each plant?

If each plant needs 5 Nickels, can I add 1 Quarter, or 2 Dimes and a Nickel?

lol:laugh::laugh::laugh: Just trying to be funny..........and I guess its not working.:dizzy:

KACYDS

Try a slow release half dollar, at the rate of devaluation it is only worth a Nickel today.

KACYDS
01-14-2009, 01:44 PM
KACYDS

Try a slow release half dollar, at the rate of devaluation it is only worth a Nickel today.

Ric,

Thanks, I knew I could count on you to have the perfect answer.

Hopefully you staying warm, with this weather we having. Was 34 here in New Orleans this morning. Suppose to be in the 20's Friday morning.

rcreech
01-14-2009, 01:44 PM
KACYDS

Try a slow release half dollar, at the rate of devaluation it is only worth a Nickel today.

Sounds like a plan....

If I had any "cents" I would help you out...but there are several on here that told me I didn't have any! :laugh:

Ric
01-14-2009, 01:50 PM
Sounds like a plan....

If I had any "cents" I would help you out...but there are several on here that told me I didn't have any! :laugh:

rcreech

There does seem to be a lack of that element here.

KACYDS
01-14-2009, 01:51 PM
Sounds like a plan....

If I had any "cents" I would help you out...but there are several on here that told me I didn't have any! :laugh:

What do they know? lol:laugh:

Most people don't realize, there are more than one way to skin a cat. We all have opinions and we need to respect that. I don't always agree with everything I read, but I don't belittle someone because their thinking is not the same as mine.

We are all here to learn from each other, and not to look down on others.:)