A question about Assignment 6

Fragment of a discussion from Course talk:APBI403

Hey Morgan,
Question #1 in the lab assignment #6 is asking to "... compare the two sets of values for soil pH and explain the differences in the values obtained by the two methods." Hence, two sets of values that should be compared are soil pH determined in water and soil pH determined in a salt (ie CaCl2).
As for determining soil organic matter by loss on ignition method, the basis for that method is that ALL organic compounds are burnt off at the temperature of 600C.
Soil pH determination is done on air-dried samples (as is the typical procedure in preparing samples for soil chemical lab analyses), not on oven-dried samples.

MajaKrzic (talk)23:09, 29 October 2017

Dear Maja In Question #2 b), it uses oven-dry organic matter content.Why use oven-dry organic matter not air-dry organic matter?

XiaoyingWu (talk)02:28, 30 October 2017

In Friday's lecture, I explained the reason why soil organic matter determined by the loss on ignition method on air-dried samples needs to be corrected. Please take a look at the lecture notes for last Friday (Oct 26) that are posted in Connect.

MajaKrzic (talk)04:25, 30 October 2017

Got it. Thank you.

XiaoyingWu (talk)05:26, 30 October 2017