Pumping o2 into the soil via Air pump.

Ghetto science with no benefits.

Pumping air into dirt will dry it out. Not a good remedy for anything worthwhile. There may be some benefit in getting more oxygen into the soil, but creating air pockets will also lead to other problems. If you have a great soil mix there should be no reason to pump in air.

Over-complicating things. If you constitute your substrate properly, it will have the optimal gas:water mixture without any contraption or additional effort. Just gonna dry out your substrate faster and probably no benefit. If you made a soil with poor drainage and aeration qualities, maybe it helps? But again... simply avoid it by constituted it correctly. lower water per volume capacity like coco coir only needs 33% perlite. Something like a potting soil or sphagnum peat moss should have 50% perlite. Perlite can be swapped out for numerous other options, too. #2 perliteteis a good size. #3 vermiculite works well. Stay away from large chunky things like wood chips and clay balls. Vermiculite also adds some available silica, which is nice. has some cation exchange sites too so it can help retain nutes unlike perlite. also if you have a reservoir of any larger size, agitation is 10x more effective than bubbles. Large aquariums use power heads instead of bubbles for this very reason. Sometimes they are called 'wavemakers'. The swirling water is constantly churning and picking up gas from atmosphere. Significantly more surface area coming into contact with atmosphere over time than bubbles slowly floating to the top. Gas goes into solution almost immediately to reach equilibrium. in smaller volumes, like a bucket for dwc, bubbles are fine. But, anything up aroudn ~30-50 gallons probably better to go with a powerhead.

I've read a little on the topic, especially in context with soils with a high clay content. I'm rather skeptical but haven't ever tried it. It would make more sense to oxygenate the water before watering IMO. As Mouse mentioned, the movement of liquid through the media should be sufficient, assuming it's not too compacted.

the roots need oxygen but they normally get that from water moving though it and pushing the old out and the new flows in behind it. I don't think they need so much air or O2 that a pump is required as if they get to dry they die. This is a different scenario when doing DWC and hydroponics with no mediums and just water. the water need to be aerated and is done by stones or surface agitation. You can also aerate your solution before giving it for extra O2 in the mix. I used to do this, I don't anymore and just go straight from the tap. it has a aerator on it and gives plenty of O2 unless its been sitting for a long time