Hi all,

The reference of Shiping to the importance of phytate is very interesting.

There is a research group working here on identifying organic P compounds who believe that there has been alot of inaccurate speciation of phytate (Smernik et al.,SSSAJ, 71, pp1045-1050). I can see this discussion is going to get very interesting with such a range of specialists!

In respect to the work I would be able to get funding for in Australia, I expect that the focus would be wheat. There has been some breeding work done in Australia to increase the P use efficiency of crops by solubilising organic P but I think this work has found limited success in field testing.

Cheers

Therese

Dr Therese McBeath

Discipline of Soil and Land Systems

DX650-DP614, Waite Campus,

University of Adelaide

Glen Osmond, SA, 5064

Ph    : +61 8 8303 8107

Fax   : +61 8 8303 6717

e-mail: therese.mcbeath@adelaide.edu.au

CRICOS Provider Number 00123M

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-----Original Message-----

From: Deng, Shiping [mailto:shiping.deng@okstate.edu]

Sent: Friday, 11 July 2008 1:47 AM

To: Raun, Bill; therese.mcbeath@adelaide.edu.au

Cc: Desta, Birehane Kasaye; deng@mail.pss.okstate.edu; jsolie@okstate.edu; Ortiz-Monasterio, Ivan (CIMMYT); Klatt, Art

Subject: RE: Foliar P funding application

Bill:

Thanks for the information and for the invitation to join the team. It would be most useful if you already have P-use efficient and non-efficient plants identified. Otherwise we can go fishing for a needle in the ocean and hope to be lucky.

The website has some interesting information exchange. With respect to global P cycling, it was estimated that about 70% of fertilizer P applied every year is converted to phytate (a P storage compound in plants). I have a reference for this, but I think that it is more likely 70% of P taken up by plants (considering the low P use efficiency for plant uptake). In any case, phytate is an important compound in the global P cycling. If resource available, it would be helpful to identify plants that have the ability to take up phytate directly (to my knowledge, there are evidence, but not confirmed). Phytate is a small and water-soluble compound. Theoretically it is possible that this compound can get inside plants without breaking down to pieces.

Should we focus on wheat or include corn and other plants as well? I suspect what we are going to try could be plant specific.

Shiping

Hi all

There is also a lot of information from Australian studies on the relative availability of phytate versus other sources of organic P to plants by only via root uptake - works ok in solution culture or low P retention soils, but not in sorbing soils as phytate is very strongly held in soil.

Nothing done in the foliar uptake area with phytate as far as I know as yet.

Could be interesting.

Cheers

Mike McLaughlin

Adams MA, Pate JS (1992) Availability of organic and inorganic forms of phosphorus in lupins (Lupinus spp.). Plant and Soil 145, 107-113.

Armstrong RD, Helyar KR  Utilisation of labelled mineral and organic phosphorus sources by semi-arid grasses.

Martin JK, Cartwright B (1971) The comparitive plant availability of 32P myo-inositol hexaphosphate and KH2PO4 added to soils. Communications in Soil Science and Plant Analysis. 2, 375-381.

Anderson G, Williams EG, Moir JO (1974) A comparison of the sorption of inorganic orthophosphate and inositol hexaphosphate by six acidic soils. Soil Science 25, 51-62.

Therese,

This is going to be fun!  Kefyalew Desta (one of our recent PhD graduates and who is now an OSU Assistant Professor) has some ideas that he will be sharing with the entire group soon.  Also, a while back we started a collaborative "non funded" project with several people identifying "P indicator plants", in this case wheat (see link below, and several articles on the site).

http://www.nue.okstate.edu/Phosphorus_Plants.htm

Ivan Ortiz-Monasterio (CIMMYT agronomist) has already started work with Art Klatt (wheat breeder) to identify "non-p-use efficient" plants that we could plant "randomly", then recognize them and treat those areas based on sensed data.  We already have some wavelengths that Birhane Desta has looked at that we think will work for recognizing P deficiencies, similar to what we have done with the entire GreenSeeker project on N.

We haven't tested the new indices but what I've seen thus far looks ok.

With time, I'll try to start a page (similar to the one we started above) where we can share thoughts on foliar P.  Lastly, Shiping Deng (Soil Microbiologist and Professor at OSU) has some pretty unique ideas on what she thinks we should be doing with foliar P applications.  With time, we just have to develop a better P fertilization strategy, especially with P prices going through the roof, and P mines that aren't "growing."  Ha.

Bill