A few miles along the road after I'd taken yesterday's photos, I passed some fields that had been sprayed with lime. I loved the sight, everything was so white and ghostly, but I'd already taken my picture and it wasn't easy to stop to take a shot of the fields. I took this one the next day and the effect wasn't quite as a good as some of whiteness had faded, but this is the only shot I actually took today so it'll have to do.
It occurs where soil is more acidic - the lime reduces acidity in the soil http://en.wikipedia.org/wiki/Agricultural_lime