Dear RJ,

there is one principal fungal taxa aiding plants in solubilizing and taking P up from the soil, and indeed they are the arbuscular mycorrhizal fungi. However, take into account that other microrganisms could also help, such as phosphorus solubilizing rhizobacteria.

Take into account that the plant-availability of P in soil mainly depends on the soil pH (and Ca, Fe and Al contents), thus, in general, every microorganism (or other condition) which can interact with soil pH can increase P availability for plants, which is the the case of almost all the mineralizing bacteria, such as PGPR.

Finally, take into account that in those soil where the available P is high, none of this microrganisms can be efficient in directly increasing P availability, but can have a indirect effect on plant growth (and P uptake, too) by removing other limiting factor which hinder P uptake (such as N availability, etc).

You can find some papers in my page and some very fine review in scholar google.

Cheers.

S.

Dear Quiroz, Sergio's answer is right and almost comprehensive. However, I like to lead some more about the question. I think it is better to see soil chemical characteristics. Working with Glomeromycotan endomycorrhizal Arbuscular Mycorrhizal (AM) fungi would be somewhat difficult: These fungi are not culturable, and their establishment in soil would be dependent on the successful symbiotic association with the plant roots or roots in a mixed vegetation. There are some bacteria like Thiobacillus fermentans and etc that decrease soil pH through oxidation of sulfur, and as dear Sergio has already pointed, reduction of soil pH could lead to more activity of soil phosphorus through its solubilization. Some soil fungi may play similar roles, then if a fungus grows fasts and decreases soil pH more faster, it would be a good fungus provided that it is not pathogenic and biologically safe. Trichoderma fungi may be good fungi, in Iran, where most soils are rich in lime and poor in organic materials, I tested the isolates of Trichoderma on the plates of soil extract agar. Some grew well. You may focus on an integrated approach of enough plasticity dependent to your soil and climate. Some plants are known to acidify soils, You may plant such plants like coniferous plants or use their composts together with fungi, or bacteria. You may use a mix of all plus chalk or sulfur. Irrigation will be required to provide a well-humid medium for microbial activity. Working with microorganisms You have to consider the optimal conditions for their activity and accordingly to adjust the action time to a proper period. If conditions are out of microorganisms potential, then You have first to concentrate on chemical approaches then on biological or integrated methods. I think this website would not bad to be referred: http://hubcap.clemson.edu/~blpprt/lowerpH.html

Dear RJ - its a very interesting, but also a very complex task you have line out. The AM fungi may definitely play an important role, depending much on soil P status and not least the type of plants you are planning to include in your work (is it an in situ study with a natural plant community or a lab study you are aiming at?). Some plants do not form mycorrhizas - some are dependent on mycorrhizas! The experimental place seems not to be an arable soil (or?) and hence ECTOs may be more important depending on vegetation. It is definitely possible to do controlled experiments with both AM and ECTOs, where you have control treatments without these fungi. But I think you need to be more precise in you study aims - in order to get more precise answers :-) Anders

Hi RJ,

I agree with the views already expressed. A lot depends on the kind of vegetation that you are considering, i.e. whether they are symbiotic with AM or ECTOs and also the fertility of the soil. In my opinion the present aims of your study are too general and too broad as there are too many fungi and other microorganisms in the soil that you would need to consider. You also need to consider whether you want to conduct your study in situ or as pot trials as this would greatly influence your study design.

Best wishes,

Su See

Mycorhiza fungi as important, also some bacterias as Arthrobacter ureafaciens, Phyllobacterium myrsinacearum, Rhodococcus erythropolis and Delftia sp. has been reported as phosphate solubilizing bacteria (PSB).

Hello

With great respect I suggest you organize your goals. As other colleagues have responded, I ask:

It is a acid soil? That pH has the soil? That concentration of phosphorus have? What crop type will be considered in the study?