In the southwest, the problems are related to corporate farming and clearing of every square foot of irrigable land. The ditchbanks and windbreaks are disappearing and there goes the habitat for quail, pheasant, doves, cottontails. There is also a lot more posted land, even bare dirt, then there ever used to be. Seems to be related to produce buyers not wanting any foreign stuff in their loads, so the farmers just post everything, whether it has a crop in it or not.