We have a terrible soil which is fill. For this reason I do sheet mulching with whatever I find. That means that my soil is probably way out of balance. I think testing would be a great idea. BUt as said I sheet mulch with whatever I find so every spot is different. I would like to know about the main nutritients in the soil but as well salt, minerals or if there is something nasty. Are there any testing kits (not those you can make 25 tests I think of testing continuously) which I can use on a constant basis? Using a lab is quite expensive if you want to get a good overview of different spots. Are there some unusual ways of testing your soils? We are in the Blue Mountains. Both Steve Solomon and Phil Nauta tell that testing is crucial.
Apart from the usual pH kits that are available everywhere, you can also find NPK kits. I think Diggers carry them for example. Soil labs test for a specific suite of things, not for everything. If you suspect something nasty you would probably need to have some idea of what it is and find a lab that is able to test for that specific thing.
one way to find out (fairly cheap to do also) is to take a few pots of soil and germinate some fast growing plants and see if anything looks wrong. you can do three pots (one the control), amend one with a little agricultural lime and the other with some sulphur, then observe... usually this will show you which direction your pH is and if any amendments would help. most people who bring in fill are hauling it from areas being excavated so contamination isn't usually a problem. is there some reason to suspect the fill you got was contaminated? is the area an old dump site? or? one thing that might give some clues would be to dig a shallow well and then take water samples and have them tested, if those show problems then you can go from there in deciding what you want to do (isolate the gardens from the subsoil and do raised bed gardens or even abandon the site entirely).
