Why are Bobolinks particularly susceptible to nest failure related to agricultural practices?

Answer

They nest directly on the ground in dense vegetation

Since the Bobolink nests directly on the ground within dense vegetation, it is highly vulnerable to nest failure if fields are mowed early in the season before the young birds have fledged.

Why are Bobolinks particularly susceptible to nest failure related to agricultural practices?
birdComparisonblackbirdBobolink