so ive been running a fixed wing for the past two seasons doing NDVI passes over our soybean and corn fields, mostly just stitching together maps in Pix4D and handing them off to the agronomist. works fine for coverage but we keep missing stuff between passes and the ground sampling distance at the altitude we fly isnt really cutting it for early disease detection anymore.

been looking hard at switching to something like the DJI Mavic 3 Multispectral or even the Agras T40 if we're going full commitment. the T40 obviously does spraying too which is the other thing we've been wanting to add. neighbor two farms over has been running one for a season and says his input costs dropped noticeably but i havent seen his actual numbers.

main concern is battery life obviously. fixed wing does 45-50 min easy, multirotors are what, 25-30 min tops under a real payload? for 800 acres that starts to feel like a lot of battery swaps. anyone running a hybrid setup or just fully committed to multirotor for everything?

we made exactly this switch about 18 months ago, dropped the eBee for an M3M and honestly the data quality improvement was worth the tradeoff on flight time. yeah you're doing more battery swaps but the 5-band multispectral on the M3M is just in a different league for picking up stress before it's visible. caught a sudden death syndrome pocket early enough last season that we probably saved a decent chunk of yield on that field.

we're not doing spraying yet so cant speak to the T40 but from what i understand the spraying and scouting workflows are pretty separate anyway ? different flight plans, different altitudes, different everything. so if your primary goal is better monitoring data id say get the M3M first and add spraying capability later if the ROI makes sense. also Pix4Dfields handles the M3M outputs really cleanly if you're already in that ecosystem.

the battery thing is real but people overestimate how bad it is once you get your ground ops dialed. we run 4 batteries in rotation with a charging hub in the truck, by the time youre done swapping and relaunching the next set is basically topped off. its annoying for the first few weeks then it just becomes routine.

also worth looking at the Autel Evo Max 4T if you havent, not as common in ag circles but the thermal plus RGB combo has been surprisingly useful for us, caught an irrigation issue we would have totally missed otherwise.