Dear Ong Tshering

 No Direct methods are available,the comparison of either nutrient concentration of mycorrhized to non-mycorrhized plants or nutrient uptake by mycorrhized to non--mycorrhized plants will reveal the difference  in biomass as well as nutrient uptake induced by mycorrhization ."A common method for measuring uptake by intact roots is the depleion method, where in intact fine roots are seperated from soil and placed in nutrient solution. The difference between initial and final amounts of nutrient in solution is attributed to root uptale."   

Depending on the plants you're using as a model , would it be easy to grow several plants with and without fungal incoculum and look at growth differences?

20 plants with fungus, 20 without and place 10 of each group under low water, and 10 with adequate water. Then compare the differences after a given time eg; height, biomass, number of leaves, average leaf area, root length, after 1 month.

regards,

Prem Baboo

https://www.researchgate.net/post/How_can_I_measure_nutrient_uptake_by_plants_treated_with_mycorrhizal_fungi?_tpcectx=profile_highlights

Nutrient uptake studies abound on the internet, I am sure you can find one relevant to your study's circumstances with additional information.

In general, plants are sampled for leaf/stem/root material, and dried in an oven at 80-100C for 24hours or longer. Pick enough plant to be representative, I would assume you are collecting whole plants for biomass as well as nutrients. Depending on the type of nutrients, do your best not to contaminate the samples with water/soil etc from the wetland. Wash the excess mud or dust off so you are not measuring the substrate on the leaves. Roots are always going to have contamination from soil, so don't expect accurate results. Maybe take more replicates and be prepared for highly variable results regardless.

Wetland plants can be very porous and have high water contents so do not pack the plants too tightly and make sure the paper bags do not break down with excess moisture before the samples dry. Dried samples then need to be ground and subsampled for the acid digestion before the AAS can be used. You will need a large grinder, as most wetland plants are large and need to be completely ground before you can subsample.  See my attached paper for sample preparation details and other procedures (mostly for ICP, but the principles are the same).

Having dug up plenty of constructed wetland plants myself, I wish you luck in your studies.

Article A cost-effective acid digestion method using closed polyprop...

Form a time series 1, 2, 4, 8 and 16 months for your bed replicates.

Throw out sample grids and harvest all plants with all portions of the plants, identify the plant composition take a dry weight and record. Grind your dry plants and take a atomic spec to determine the % of nutrients by dry weights. Normalize your data on kg/ha yield basis and use percentages to determine the exact amounts taken up.

If you have different treatments the yields and amounts can be compared using an area under the yield of nutrient curves for comparison.

Thank You everyone..for your kindful help

Paul--excellent--can you provide any literature? Looking for a rough estimate of nitrogen assimilation, uptake, and denitrification per acre of forest.

Dear Frank Piccinni, I have attached a document which I hope you find helpful in relation to doing sampling for your experimentation. All the best, PRH

check out my project, it might help to answer your questions https://www.researchgate.net/project/Influence-of-Water-Composition-on-Plant-Biomass-and-Biochemistry

Determine the sample dry weight and multiply by the nutrient element concentration of the sample.

I dont know why u dont find the procedure, it is well known. Take specific amout of plant samples(leaves, roots etc) digest it in di acid (HCLO4: HNO3 3 : I) OR ANY ACID given in the method. Make the volume in 50 or 100 ml whatever convenient. Make the graph curve for that specific nutrient u going to measure. Run the sample in the Atomic absorption and not the absorbance . find the concentration with the help of graph

Is (or approximately) plat Annual N uptake = Annual NPP * N%