jheight2 said:...
So minerals and nutrients are the same thing? i was under the assumption that plants need rocks to get their minerals, that's why i put the red rocks in there. Since perlite is a rock, i think that will do.
I think the problem is a combination of many things. ...
I can take my experience and teach it to my students so they can learn not to do what i did. :)
Congratulations! We all learn by trial and error. You might have learned three years worth of lessons in just a few weeks!
>> So minerals and nutrients are the same thing?
In very mature soils, minerals have had centuries to crumble into fine grians, and those grains have had centuries to break down and for their outer layers to dissolve. Lichens and fungi help that process go faster, as does humus in the soil (humus + microbes produce humic acids, which eat away at rock grains).
That process, over 100s or 1,000s of years, slowly releases the minerals into a soluble form, at which point people start calling them plant nutrients. Plants take them up very aggressively so you seldom see much soluble Nitrogen, Phosphate or Potassium in the soil. (or other plant nutrients like Calcium, Magnesium, Iron, Sulphate etc.).
Plants capture the available (soluble) nutrients and build them into plant tissues. If the nutrients are not being leached out and washed away by rain or fire, the plants standing in an area can be thought of as holding all the nutrients slowly extracted from the minerals in the soil over many years.
Once in a plant, those nutrients are MUCH more available. As each plant dies, it composts or is eaten and releases those nutirients back into the soil in very soluble form .. where more plants grab them up and build them into their tissues.
It's like having two bank accounts: one that has long-term bonds and investments like real estate and companies. Those very gradually give off profits that you can gradually put into your checking account, where they are rapidly available and you can do whatever you want with them without wiating 100 years.
So there are three main ways to increase the fertility of soil in a bed or pot.
You can wait 500 years for minerals to slowly leach out of finely crushed rock powder, or wait 50,000 years for them to slowly leach out of pebbles or grit.
You can make or buy compost, and those solublized minerals are available within days or weeks as the compost continues to break down. Or keep a layer of mulch over your beds - it will break down and release nutrients over a year or three.
You can buy chemical fertilizer - soluble or pellets - and it's available the minute it hits moisture. That why you have to be careful to avoid adding too much fertilizer - one scoop is the equivalent of thousands of years of leaching from rock dust so it's easy to overstimulate the plant.
Plus, any soluble mineral is by definition a kind of salt, so you can kill the plant with excess saltiness.
Plus, chemical fertilizers are not necessarily pH-neutral, so you can kill a plant with excess acid.
Plus, many nitrogen compounds are both acidic and toxic if excess is present.
I think that's four different ways that chemical fertilizer can kill plants, especially young tender plants. I think people lump all four together when they say "burned by excess fertilizer".
My own policy is to use the
least amount of chemical fertilizer I can without plants getting yellowish and stopping growth. It's the same policy as not watering until (just before) they wilt a little.
That's part of the same policy as adding
as much compost as I can make or afford (not enough, since I'm cheap). It's safer and much better for the soil, and vital for the soil life that
lives on the organic matter in compost.
In practice, I'm TOO cheap because the soil would be much happier if I bought and carried and spread much more compost and mulch than I do.
P.S. The process of very gradual leaching of minerals from rock dust is why some people buy powdered rock every few years and spread it in the garden. The rare micro-nutrients that plants need in tiny trace amounts can probably leach out of rock dust fast enough to replace whatever is lost from soil.
http://www.azomite.com/
Since rocks only "dissolve" from the surface, rock dust "dissolves" much faster than rocks, pebbles, grit or sand.
