Agree that many WPAs have gone bad ... thistle, buckthorn, single cedars, are often popping up ...
I have a problem with how some of these plans are run.
In an era when nesting grasses are disappearing at an alarming rate (CRP losses), converting entire WPA land areas to crop land is somewhat disturbing ... especially on a 5 year plan.
There are a couple of large WPAs in ND where they are farming nearly every last acre except the wetlands ...
no real grass buffer strips 
Lack of buffer strips is also seen on small WPAs being farmed too ... Come on now ... don't they know that grass buffer strips prevents the water from taking on too many chemicals ... algae blooms, etc... and buffer strips prevent silt intrusion from run offs.
I would argue that they could plant 120 - 160 acres at a time and rotate through over multi time periods ... leaving the remaining quarter-to-half section in grass.
Hopefully the US government is charging reasonable lease rates on these farmed acres.
Fire and grazing have shown to be effective management techniques too. On another ND WPA ... they had cattle in what appeared to be newly (1-2 year old) grass stand ... largely bluestem. The grassy area was largely dirt with clumps of grass starting up ... the cattle had "damaged" the soil during wet periods.

My uncles grazed their land rather heavy (if not aggressive, but they never treated the land that way).
Never seen a sign at a single ND WPA explaining time table ...