Question
A certain area where my lawn is suppose to grow, not much
grows there, including weeds. when the area is dry a white
powder forms on the surface. I am told this is a form of salt? Is
this true? Is there anything I can do do neutralize it.

Answer
One way to tell if it is a salt, taste it. Just wet your finger and touch the white stuff, and touch it to your tongue. If it is salt, you will taste it.
I can't think of anything that it could be that a tiny touch of it would harm you.
You can take a sample of the dirt with the white stuff on it, and send it to be tested.
Call your Agricultural Extension Agent, for your area, they can tell you what it is likely to be, or where to send the soil sample to get it tested. They can also tell you if it can be gotten rid of, and how to do it.
House plants, after a while get a salt like deposit on top, and you put the plant in a sink or bathtub, and leach it. You pour water on it till it soaks the salt and it washes over the top. and cleans the soil.
I suppose that could happen on outside soil, I have just never experienced it.
There are a number of things that could be white. It could also be white powdery mildew. a fungicide sprayed on the area should fix it, or disolve baking soda in water,and soak the area well with it. I use baking soda instead of commercial fungiides, because it works better for me, and doesn't harm my little critters that eat the bad bugs off my roses.
You might treat it as a fungus first, that would cost less than the testing, although that is not very costly.
But if it is a fungus of some kind, it would be fixed after a good soaking with a fungicide.
If it is salt, it must be leaching up from underneath, unless you have recently moved there. A previous owner could have put salt there because they didn't wany anything to grow there, like the had a pool there or something.
I read once, that if you have some conditions, and need to sterilie the soil, on a very hot day, above 85 or 90, put black plastic over the area, and let the hot sun literally cook it. It heats the soil to a temperature high enough to kill the germa, and will leave you with sterile soil, without the disease that was there.
I have no idea if this would work on the problem you have. If it is salt, I can't see that steilizing would help.
I would get it tested, or at least talk to a local nurseryman who is familiar with the problem, and knows if there is a solution.
It is hard to believe that salt, in just that one spot would form. Seems like salt would be a problem that a larger area would be effected.
This is really a puzzler.
You could look up the website for state agencies in your state. I think every state is maintaining a website, and you could possibly connect with your Agricultural Extension Agent, or with the Horticultural education pages. you might find the answer there.
If you are not too familiar with this type of searching, write me the state you live in, and I will search it for you.