Using high Potasium feldspar for fertilizer

[jbander]

Has anyone ever used feldspar for potassium in their garden, if so how much have you used per 100 SQ FT. I'm a potter so I have lots of Feldspar here, Custer feldspar is 10% potassium. I was thinking that maybe it was really slow release and thinking about using a little hard wood ash with it to. Well that is if it breaks down faster then the feldspar, I guess thats a question also.

[lily51]

In order for a plant to use a compound, it has to be water- soluble.
Feldspar is a compound called a silicate like sand is. it is in crystalline form
And isn't soluble. It's release is so slow as to be called unavailable.

Potassium for fertilizers is in a whole group of compounds called "potash"
You're on the right track with wood ash as that was processed for potash
before it was discovered that the compounds could be mined.
Hope this helps a bit.

[TheSilverSurvivor]

Wood ash is great to add directly to your garden, but it can raise your PH level in large amounts so check your PH before hand and add wood ash in stages, checking your PH in between. Start with one pound of ash for 100 sq. ft. and see what happens.