Can carbon that has been taken from waste tyres be put back into the soil

Yes, but you probably want to remove any toxic contaminants first. I don't think it would be worth the effort.

I'm a novice at this, so need all the help i can get. I have had it tested and it looks like theres less than 3% sulphar in it. do you think this will have a negative impact?

Sulfur is not going to be problematic in small quantities. It is mostly other contaminants that I was worried about, especially metals.

 

http://en.wikipedia.org/wiki/Tire_recycling#Environmental_concerns

I think tyres are slow to biodegrade, due to the vulcanization. Some gardeners use sulphur as a soil amendent to lower the pH, it seems to me sulphur is not very toxic, although some compounds like hydrogen sulfide is said to be toxic. The article below says there is some potential carcinogenic compounds in tyre dust.

 

...http://www.ehhi.org/reports/turf/health_effects.shtml

Edited September 13, 201015 yr by skyhook

How would you do that? I'm sure you don't mean burning the tyre and allow photosynthesis to do the rest.