The farm we go to rotates which field is used as their season pumpkin patch on a year by year basis. We wondered if there was some crop rotation benefit to doing that, like maybe pumpkins fix nitrogen so they’re a good intermittent crop between other nitrogen depleting species.
Cucurbits (squashes, gourds, pumpkins, zuchinis, etc.) are heavy feeders. They use a lot of nitrogen, require fairly rich soil. So they're typical grown in recently amended soil. So growing them multiple years in a row in the same spot has some challenges.
They attract quite a few pests (fungal and insect). But those pests tend to be specific to cucurbits (or Cucurbitaceae, including melons, etc.). So it's a good idea to rotate them out so that overwintering pests in the plot don't have a free snack the next year.
Finally, they make a good crop to plant at the beginning of a rotation because they grow quickly and cover the ground, blocking the sun and drowning out many weeds. So a good way to bring new land into production or to get some perennial weeds out of a plot that you want to use for something else the next year.