Hello tommaldito,
Not actually located at the Phillippines but in S.E.A though (as you know), - I'd recommend to either contact the Department of Agriculture (Kagawaran ng Pagsasaka) http://www.da.gov.ph/ in Manila, or directly the FARMERS' CONTACT CENTER "Ang Inyong Kaagapay sa Usaping Agrikultura"

Call :
1800-10-982AGRI (or 1800-10-9822474) - for provincial toll-free calls
02-982-AGRI (or 982-2474) - for Metro Manila
0920-946AGRI (or 09209462474) fro mobile calls

391DA (or 391-32) for Smart and Talk 'N Text subscribers
0920-946AGRI (0920-9462474) for Globe, TM and Sun Cellular subscribers

Email :
info@e-extension.gov.ph

They should be able to point you in the right direction (if they aren't, who would be?) or the farmers contact center, which looks like an extension of the D.A. -they may even directly provide what you need if you are lucky.

Good luck with that,
Cheers,
Lucas

Here is a link that might be useful: Kagawaran ng Pagsasaka

Dear Tom

We shanxi jiaocheng hongxing chemicals co.,ltd from China

Mainly manufacture kinds of fetilizer ,such as : calcium nitrate , magnesium nitrate, calcium ammonium nitrate ,potassium nitrate ect

If need more information ,please let me know

Kind regards

Lena
Shanxi jiaocheng hongxing chemicals co.,ltd
www.china-hxchemical.com
Email : lena@china-hxchemical.com
Skype : lena.hxchemical

Hi Tom,

Please contact me by email sanxichem@263.net.

Zhao + 86 -13934162383

Hi Tom,

May i know the supplier for analytic grade potassium nitrate? We need it for our Lab. Thanks!

Nice....!!!

https://www.elawoman.com/