How is depleted soil recycled?

[PhytoFighter]

I've planted a plant into a pot and it has grown well and matured and flowered. I wanted to get rid of this plant and plant something else into the pot - but I am assuming right now that the plant that has grown has depleted the nutrients in the soil and that the roots and stems of the plant that are going to remain when I remove it from the pot won't allow for new plant growth - or will hinder it in another way that I am not aware of yet.

Is there a way I can recycle the used soil, root, and stem matter and make the soil as viable as it was when I made the original planting? Or should I just take out the current plant and seed the soil with the new specimen and wait for it to make a home for itself on its own?

I did a Google search and figured out that the fertility of soil has to do with nutrient, mineral, pH level, microorganisms, drainage, and decayed plant matter levels. What a mouthful.

Suddenly my organic waste basket is looking awfully attractive.

Are there any tools I can use to measure pH levels, nutrient and mineral content, and test for microorganisms?

Also I'm not sure if this falls under the category of composting, organic gardening, or indoor gardening.

[Kisal]

You can recycle the soil by adding it to your compost pile, where it will become mixed with decomposed organic material, fresh nutrients and good bacteria.

Or, you can remove it from the pot, take out as much of the old plant's root system as possible, mix in some compost, maybe some worm castings, and definitely some sharp sand and perlite. At that point, it should be good as new again. Clean the pot, fill it with the renewed soil, and plant.

You can buy soil testing kits at most good garden supply centers. If you're near a major university or office of the Agricultural Extension Service, they sometimes offer inexpensive soil testing services.

[hendi_alex]

I recycle my potting soil many ways. Sometimes it goes into the compost pile. Other times it goes into the soil wheelbarrow, gets fresh amendments such as fertilizer, perlite. maybe a blend of fresh potting soil, maybe an addition of some compost. Then back into a pot with a fresh plant. The plants most always do fine, and even when they don't, I doubt that it has anything to do with the soil.