Caffeine in soil

I did a web search to see if the effects of caffeine in soil has been studied. It has. Too much caffeine will inhibit root growth. Of course, caffeine gets broken down by certain bacteria, so the levels of caffeine will depend upon how recently the caffeine has been added to the soil

I will be modifying my gardening techniques to avoid the use of fresh UCG in the springtime. I will also be sure to add compost to those areas where I had previously applied UCG.

I suppose the regular application of UCG will ensure that the appropriate bacteria (Pseudomonas) remains available for the decomposition of caffeine.

This spring, I had turned a lot of coffee grounds into a bed where I was attempting to grow peas. The germination rate was disappointing and I wonder if the fresh coffee grounds were to blame.