@Elizabeth Jackson good question, and honestly really relevant for ag deployments specifically.
The 50km figure is the drone-to-drone spec, so both modules elevated — that's where you get the best case because you're eliminating ground reflections and multipath almost entirely. For your scenario with grain silos and tree lines, you're not in that ideal case, but flat farmland is still about as friendly an environment as you're going to find in a real deployment.
The RF front-end does have meaningful link budget headroom built in — that's kind of the whole point of the external amplifiers and the receiver sensitivity optimization on this thing. Light NLOS like a tree line or a low ridge isn't going to kill the link, it'll just eat into your margin. The honest answer is that 50km becomes something more like 20-35km in your described conditions, depending on how dense the obstructions are and whether you've got any elevation on your nodes.
Grain silos are the thing I'd watch most carefully — dense metal structures at 2.4GHz can create pretty ugly reflections and shadow zones. If you can plan your node placement to keep line-of-sight across the majority of your coverage area and treat the silos as edge cases rather than the middle of your link path, you should be in good shape. Worth doing a site survey pass with just two modules before you commit to a full deployment layout.
