A highly complex process:
1) hold fart between thumb and forefinger.
2) with the thumb and forefinger of the hand separate the fibers of the fart*.
3) Repeat this process for a number of farts acquired at each field location.
4) combine and thoroughly mix fibers from all farts.
5) sub-sample 5g of fart fibers and place in glass beaker
6) add 100ml of deionised water and mix thoroughly for two minutes and leave for one hour
7) filter fart mixture through Whatman 42 filter paper (this may take some time)
8) the acquired solution can now be subjected to rigorous chemical analysis (such as nitrate, phosphate, conductivity, pH) using standard laboratory methods.
* If the fart is particularly sandy use the Patmore (2010) Peel Method.
Results to follow...bet you can't wait!