Please consult Chemical Analysis of Soil Plant and Water by Chapman and Pratt..

Though method would depend upon which nutrient are you talking about...nitrogen could be estimated using Kjeldahl distillation method or alternatively Auto Nitrogen Analyser hai g Dumas method..Phosphorous still gives best results with yellow colour vanadimloybdo phosphoric acid method and potassium flame ohotometrically

I agree with Anoop about N digestion, and you might consider colorimetry (salicylate) instead of distillation if you have large numbers of digests. With respect, I prefer the Murphy and Riley blue method for P and flame AAS for the metals.

Hi Paul and anoop, thanks for thr response. Can you suggest make and model of atomic absorption spectrophotometer and spectrophotometer?

thabks,

bhupinder

There are many. We have been using Perkin Elmer USA and GBC (Model 920) Australia for A AS and spectronic 21D spectrophotometer...

How many samples do you envisage in your project? If it is for a few dozen plants at the beginning and end of an experiment, you may be much better off for both time and money sending your samples to a fee-for-service laboratory, rather than attempt to peform the work yourself. On the other hand, if it is a regular mesurement regime (or the researcher in charge requires you to perform the work yourself) and you are prepared to spend time developing your technique on lab skills, then the do it yourself plan may be better. Even so, discussing techniques with a commercial lab may be helpful in suggesting appropriate methods for your particular project.

Hi Matt, We will have around 1500 soil samples and 1500 plant samples. I am thinking to buy an ICP-OES but still not sure about measuring ions, may be an flow analyzer. Therefore, I am looking for more suggestions.

Whether you analyse soil sample or plant sample , you need to extract nutrients from soil using a variety of extractants or need to digest them in case of plant samples before analysing their concentration with the help of different instruments having their merits and demerits both , with reference to one or other nutrients. No instrument will ward off preliminary sample preparation. You can consult some commercial laboratories if high repute. PAU is so well equipped, they can help you what you want...

Hello Dr. Srivastava, we will do our extractions and infact this is the whole reason to start doing analyses on our own. In southern US, few states have switched to Mehlich 3 from 1 but at South Carolina, we are still using Mehlich 1. Our soil testing lab is well equipped to make that change. However, we first need to compare results with two extractions from different management practices and land use. I am planning to devote some of my time in this direction. Thank you for your responses.

nitrogen by khildal

phosphors by spectrometer

potassium by flame photometer

Folks, just to update you that we have Perkin Elmer 8000 Instrument now to run plant and seed nutrient concentrations. For N, we are planning to standardize diffusion jar methods as given in the following reference.

Stevens, W. B., R. L. Mulvaney, S. A. Khan, and R. G. Hoeft. 2000. Improved diffusion methods for nitrogen and 15nitrogen analysis of Kjeldahl digests. J. AOAC Int. 83:1039-1046.

Thanks again for the input.