That is very cool Lucius. Here's something to keep in mind.
When the plant is mature, so is the microbial universe in your soil. Cations and Anions are sequestered. Plant Enzymes also. Bacteria / Fungus ratios are just the way the plant wants them. Miles of fungal networking is in place. It's excellent and getting more perfect with each passing week.
When you chop the plant, the roots die off, and many of the the microbes will go dormant if no living root system is discovered. When you leave the root ball alone and don't rinse / flush, you also leave the efficient microbial universe in tact. When you introduce a new seed or clone into the same pail, the efficient and existing microbial network will immediately plug into the new plant and swarm it, and protect it. The old root ball will be composted completely and stored for the new plant.
We enjoy working in the soil, but we should leave it alone once it's doing it's thing. My best piece of advice for amendments is make your own worm castings in a smart pot in your basement. Turn your food scraps into the best soil amendment there is. Vermicompost has been lab-proven many times to give the soil and plant huge immune system support. Recent lab testing shows that there is also huge insecticidal assistance with vermicompost also.
http://www.cals.ncsu.edu/entomology/cardoza Assuming it's quality and fresh. Make your own, all it costs is a $15 Thirty gallon smart pot