White film on soil keeps grass from growing

Last year we planted our lawn. There are a several areas where there is a white film on the soil and grass will not grow. My dad thinks that it is from where the builders washed out their paint brushes. I can not imagine that the paint would still be in the soil after a year, but I don't want to rule anything out. My uncle thinks that it is from the water discharged out of our sump pump - the discharge from our water softener gets dumped in the the sump dump, so there is some salt being discharged onto the lawn. However some of the spots with the white film are not very close to where the water from the sump pump comes out.

Any suggestions regarding what this film could be? And more importantly, how can we get grass to grow in these areas?

Do you know what kind of salt your water softener uses? I don't have a water softener, but I think I've heard that some of them use sodium based salts, and sodium is bad for plants. I've never seen something like what's in your picture, but if you've got discharge from the sump pump and your water softener system dumps into there then excess salt definitely could be killing the grass (even if it's a non-sodium based salt, I can't imagine having a lot of it in your soil is going to be good for your plants). And white stuff on top of the soil is consistent for what excess salt could look like when it's in water that's discharged on top of the soil and then the water evaporates. As far as why some of the areas are farther away from the sump--water can travel, it can move through the soil to some extent once it soaks in, and it can also run off if there's a lot being discharged at once. So if it's on completely the opposite side of the yard then it's unlikely, but if it's in the same general area then it's definitely possible that the salty water traveled a bit.

If salt is causing your problems, the only way to get grass to grow there is to find another place to discharge stuff from the water softener, then you'll probably have to give the soil some time and lots of rain/watering and some good amendments to flush the salt out and get the soil healthy again, then you can plant there.

I'd take a sample of that soil -- without disrupting the white on top, to the County Cooperative Extension office for testing.

T
Theresa

Any detergents? Detergents can form a soil surface crust that seals out oxygen and water infiltration.

Dumping your "hard" minerals can "lock" up the nutrients not making them available to plants. If those are low spots, or areas that pool then those spots may be mineral dumps and not making nutrients available to the plants.

Lastly, and I just love throwing words out there your soil may be "hydrophobic" in those spots. Read up on hydrophobic soils at http://www2.dpi.qld.gov.au/extra/pdf/hort/water_repellency.pdf and tell us if you think that may be it. If it is, you have to use a surfactant to get the water to penetrate it, then must keep it wet and eventually it will no longer be hydrophobic.