Green fields

Well, although Katowice is an industrail city (bordering with other industrial cities), there seems to be some agriculture here (this photo was actually takien on the way from Siemianowice Śląskie to Bytom).
Researchers in ecology claim that the Silesia region is "the most exposed to [ecological] hazards, in terms of both the concentration and range of excessive pollutants". What do they grow in this filed than? :-/