@Susan Gonzalez good question and honestly one worth being straight about — the 50km figure is the drone-to-drone spec, meaning both modules are airborne and you've eliminated ground reflections and obstructions entirely. For your use case with fixed ground nodes, you're looking at the 5km ground-to-ground rating as a more realistic baseline.
That said, rolling farmland with 100-200m elevation changes isn't the worst terrain you could be dealing with — you're not fighting dense urban RF noise or thick forest canopy. The bigger issue is whether your nodes have any meaningful line-of-sight to the gateway, because even a hilltop or elevated mounting point can dramatically change what you actually get in practice. Fresnel zone clearance matters a lot at these frequencies, and a node sitting in a valley depression will behave very differently from one on a ridge.
Honestly the most useful thing you could do before committing is mount one node at your farthest planned location and do a quick range test — the module's receiver sensitivity is the real differentiator here, so you might be surprised what it pulls through partial obstructions. If you want to share a rough sketch of the site layout I'm happy to think through placement strategy with you.
