I can't stay muzzled any longer.
With all due respect to you Dave and the mad scientist that obviously lives with in you. Why would you put anything into your soil as a nutrient source when you have no idea what the NPK is or know if it can be absorbed in the method your administering it...i.e zinc, iron. Also with the coffee your Ph must be heavy on the acidic side something that does not bode well for a target of neutral Ph soil
This approach to feeding seems a bit cavalier .... there are recipes out there that are figured out to the ounce for each ingredient.....You say your trees are doing alright...but does that mean their not dead yet...or ... there growing with vigor and thriving.
Tom, I don't know the exact NPK ratio of what I'm using, but I understand what an NPK ratio is and I reached this point by starting with very little of both ingredients and adding more or backing off as needed, until reaching the point I'm at presently. This isn't something I started doing yesterday. Nor is it something I just threw together.
And of course zinc and iron aren't available to the plants in the form they're applied. But small amounts will become available as they react with their environment. As these are micronutrients, I don't see why this is a problem. (As I understand it, they're usually dosed in the ranges of ounces and pounds per acre.) Sure, I could research to find their most available forms, order those exact compounds, and measure out the right amount down to the granule each time I fertilize, but would my plants really be noticeably better off for it?
As for the pH, I think I would actually be aiming for a soil pH of about 6 to 6.5 instead of neutral for nearly all of the plants I have. I don't presently have good equipment to test the current soil pH. I've tried getting one of the cheap meters they have at Home Depot for it, but I found it to be really unreliable. When it worked, it was telling me I was close to my mark. Getting something better to measure soil pH is on my to-do list, but that's going to have to wait for availability of funds.
However, I will say that since nearly all of the acids in coffee are weak acids and ammonia is a weak base, it shouldn't be that difficult to combine them in a weak solution and get something close enough to a pH of 6 or 7 that it won't burn roots. That is, with a basic understanding of what you're working with.
lol
