Introduction: We are doing research on the possibility / potential of
fortifying fruits and vegetables by adding nutrients to the plant root
environment.  We are especially interested in produce grown
Aeroponically (e.g. grown with the roots suspended in air and are
misted at period intervals with a nutrient solution).  Preliminary
research shows that there is a greater uptake of iron, potassium, and
other essential minerals because roots are exposed and are being
misted directly.  We are following this line of research to gain a
greater understanding what other vitamins and minerals might be taken
in through an Aeroponically grown plant’s roots and into the ultimate
fruit.

Here are my questions:

1. What research has been done to date on the subject of root
assimilation and nutrient uptake (not necessarily Aeroponically)?  Who
is working in this field and how do we contact them?

2. What nutrients can plants assimilate through their roots?  (i.e.
Can plants assimilate calcium?  Iron?  Folic Acid?  Anti-oxidants? 
Vitamin B12?)  Are there any academic theses out on this subject?

3. Has anyone produced a nutritionally fortified fruit or vegetable? 
If so, who and where?

4. What is the difference between root assimilation in dirt grown
plants vs. hydroponically grown plants vs. aeroponically grown plants?
 THANKS!

Hello,

There is a lot of research out there on the nutritional uptake of
roots.  I have listed some of the individuals and institutions who are
doing research that might be of interest to you.  I have also listed
some of their research that might be helpful.

For the most part, research on the uptake of nutrients focuses around
N, P, C, Ca and Fe.  I could not find any research on root uptake of
vitamins.  Some of the individuals that I have listed may be able to
answer that question.  In most cases, the research suggests that
nutrient uptake by the root is increased when the plant is
experiencing a deficit of that nutrient.  A result of this there
appears to be a maximum nutrient concentration in the soil above which
the plant no longer increases uptake.  The plants seem to reach a
maximum assimilation level, and does not take in a “super nutrient
load”.  There are however, some papers that address some ways to
increase this assimilation, particularly iron.

As for various ways of growing plants.  The research I found suggested
that hydroponics was used primarily as a way to more carefully control
the environment, not as a means for greater root assimilation.  The
one exception I found was concerning the beneficial effects of
increased uptake of CO2.  CO2 intake is easier in hydroponically grown
plants than in the more traditionally grown plants.  Also, water
quality and nutrient concentrations in the water has a greater effect
on hydroponically.

However, I did find these papers.

A review of factors effecting plant growth
http://www.hydrofarm.com/content/articles/factors_plant.html

Comparing continuous lettuce production in nutrient film technique and
floating hydroponics by Both, A.J., S.S. Scholl, L.D. Albright, and
R.W. Langhans. 1998. in Proceedings of the 15th International Lettuce
Conference and Leafy Vegetable Crops Workshop. September 23-26, 1998.
Atlantic City, NJ. pp. 16-17.

Coordinated management of daily PAR integral and carbon dioxide for
hydroponic lettuce production. by Both, A.J., L.D. Albright, and R.W.
Langhans. 1998. in Acta Horticulturae 456:45-51.

Effect of dissolved oxygen concentration on lettuce growth in floating
hydroponics. By Goto, E., A.J. Both, L.D. Albright, R.W. Langhans, and
A.R. Leed. 1996. in Acta Horticulturae 440:205-210.

Whole crop simulation model of water and nutrient uptake within a
recirculating hydroponic system: a literature review. By M athieu,
J.J., L.D. Albright, K. Kurata, and E. Goto. 1998. in 2 pp.



Individuals working in this field.

William Hallmark, Professor of Agronomy at Louisiana State University
Agricultural Center is researching ‘the effects of soil P and K and
soil bulk density on the nutrient uptake and nutrient status of
soybean seedlings.’  A list of his papers and his contact information
can be found at his website.
http://www.altavista.com/web/results?q=%27root+assimilation%27+%27nutrient+uptake%27+research&kgs=0&kls=1&avkw=xytx


The research of an Associate Professor in the Department of Soil
Science at University of Wisconsin-Madison may be of use to you.  He
is working on, among other things, the ‘diffusion and transport of
plant nutrients to roots’.  His web page, that is listed below
describes his research, lists many of his papers, and gives contact
information.
http://www.soils.wisc.edu/~barak/
A&L  Canada Laboratories Inc. are studying the effects of increased
nutrient fertilization on the uptake of soybeans.  They have found
that increased N in fertilizer actually decreases uptake by plants.
Contact information is located on the webpage.
http://www.al-labs-can.com/tech_NitroSoy.html

Plant Nutrition Department at Estacion Experimental de Aula Dei:  This
page has contact information for a group of individuals who are
working on iron uptake and soil efficiency.
http://www.eead.csic.es/en/lineas_investigacion/08_fisiologia_estres.html

The Blueberry Research Project Team, located at Nova Scotia
Agricultural College are doing research on nutrient uptake by
blueberries and the allocation of nutrients in the aboveground parts
of blueberries.  Their contact information is located at this webpage
http://www.nsac.ns.ca/envsci/research/blueberry/contact.htm



Nutrient assimilation by roots.

A paper listed on Phillip Barak’s homepage describes how they directly
tested whether or not increased calcium in fertilizer would increase
calcium content in snap beans.  They found that genetic differences
between the snap beans were more important than amount of calcium
applied.
Miglioranza, E., P. Barak, K. Kmiecik, and J. Nienhuis. 1997.
Comparison of soil and genotypic effects on calcium content of snap
bean pods. HortScience 32:68-70.

This research group is looking at the N uptake of blueberries compared
to the timing and the amount available in the soil.  They discuss the
increased nutrient concentration in various parts of the plant with
application of fertilizer.
Wild Blueberry Research program
http://www.nsac.ns.ca/envsci/research/blueberry/res_act_docs/nutrient.htm


Here is an article that discusses nutrient uptake in roots.  It
describes experiments that demonstrated a plant living with a limited
nutrient resource, will increase it’s nutrient uptake.  There are
references available at this site.
Nutrient Uptake
http://www.botany.ubc.ca/biol351/351g.htm

This article ‘N uptake and distribution in crops.’  Discusses the
effects of N & C in the soil and the amount of uptake in various parts
of the plant.
Journal of Experimental Botany, vo. 53, No. 370
http://www.plantstress.com/Articles/min_deficiency_i/N%20uptake.pdf

Molecular Mineral Assimilation Department
This is a departmental site for the Society for the Advancement of
Cultivated Plant Research.  It is an institute located in central
Germany.  They are doing research on the uptake of iron and sulfur
into plants.  There is a list of references at the site some of which
describe means of increase uptake.  Contact information is also
located at this webpage.
http://www.ipk-gatersleben.de/en/02/06/05/

Calcium Rich Potatoes.  The researches in this study have managed to
get potatoes to take up more calcium into the tuber.
http://www.ars.usda.gov/is/AR/archive/mar03/gene0303.htm



Keywords Used: 
'root assimilation' 'nutrient uptake' research

://www.google.com/search?hl=en&lr=&ie=UTF-8&oe=UTF-8&q=%27root+assimilation%27+%27nutrient+uptake%27+research&btnG=Google+Search

http://www.altavista.com/web/results?q=%27root+assimilation%27+%27nutrient+uptake%27+research&kgs=0&kls=1&avkw=xytx


‘root assimilation’ research Iron OR Anti-oxidants OR Vitamin

://www.google.com/search?q=%E2%80%98root+assimilation%E2%80%99+research+Iron+OR+Anti-oxidants+OR+Vitamin&btnG=Google+Search&hl=en&lr=&ie=UTF-8&oe=UTF-8&as_qdr=all


nutrient assimilation roots research
://www.google.com/search?q=nutrient+assimilation+roots+research&hl=en&lr=&ie=UTF-8&oe=UTF-8&as_qdr=all&start=0&sa=N

assimilation  research hydroponic
http://www.altavista.com/web/results?q=assimilation++research+hydroponic++&kgs=0&kls=1&avkw=xytx&stq=0


I hope this helps. 

PbA
Google Answers Researcher

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Request for Answer Clarification by deepforest-ga on 17 Jun 2003 15:28 PDT

Thank you so much Peggy-Bill. You gave us a wealth of resources here.
I am almost ready to rate the answer and pay you, but I need to check
with you first on one thing. I do not see any answer/resoureces for
our all important question #3 "Has anyone produced a nutritionally
fortified fruit or vegetable? If so, who and where?" Could you please
provide any info on this specific question. Much appreciation. Deep
Forest

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Clarification of Answer by peggy_bill-ga on 18 Jun 2003 12:03 PDT

Dear deepforest,

I have looked extensively for the answer to the question as to one can
enhance nutritional value of fruits and vegetables by enhancing
nutrient input.  From what I have read, the answer is “only up to a
point”.  It is true that I didn’t find much in the way of experiments
attempting to do this.  However, it seems that the assimilation of
nutrients increases with application of nutrients up to the maximum
level. Essentially, when nutrients have been a depleted resource,
additions of that nutrient will increase root assimilation.  Once that
nutrient is no longer limited, uptake no longer increases.  As far as
I can tell, fruits and vegetables cannot be ‘super saturated’ with
nutrients.  Although, I did not finding any studies showing this
conclusively.  As far as I can tell from my reading the ‘maximum
level’ is genetically and individually determined.  Most of the
resources on increased nutrient value of crops have to do with plant
variety and genetic modification.

I found these articles that may be of interest to you.  They do not
directly answer your question, however, they may give you some new
insights and additional places to look.


Enhancing the crops to feed the poor
http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v418/n6898/full/nature01015_fs.html

Feeding the world in the twenty-first century 
http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v402/n6761supp/full/402c55a0_fs.html

Agricultural sustainability and intensive production practices
http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v418/n6898/full/nature01014_fs.html

Effects of nutrient patches and root systems on the clonal plasticity
of a rhizomatous grass. by Elisabeth Huber-Sannwald, David A. Pyke,
Martyn M. Caldwell, Susan Durham in Ecology, Issue: Oct, 1998.

Thanks for your question.  I am sorry that I haven’t been able to find
an experiment that directly answers your question  But, I hope this
helps you on your way to a better understand of your research.

PbA

Thanks again for your thoroughnes.  We now understand that this field
is basically uncharted territory.