Q. I have access to lots of chicken manure. Shouldn’t I use it, since it’s almost free?
A. If you’ve got it, use it. However, the vast majority of people who want to grow gardens do not have ready access to it, and that is one of several reasons we don’t teach and advocate its use.
Chicken and turkey manures are “hot,” with almost twice the amount of nitrogen that cow and horse manure have. This is because the urine and feces are together. And they can easily burn your seeds or seedlings, unless you put them into the ground several months, or at least weeks, before planting.
Another problem with using any manure or compost, or combination, is that you have no concrete idea what they have in them, so far as nutrition is concerned. They are the digested (or composted) remains of organic material that itself may have been deficient in some or all of the essential nutrients. And the processes of digestion and composting take some of those nutrients away, so they are likely to be less than ideal.
And finally, manure and compost may harbor weed seeds, bugs, and diseases, which we certainly don’t want to introduce into our garden.
We want to leave as little to chance as possible, and grow healthy plants fast. Therefore we feed them small amounts of natural mineral nutrients, that have just what the plants need to maximize their health and growth.