In the Field – Drones in Agriculture

Operating a mapping mission on the side of a road over a 20 acre plot, fortunately near to larger pylons. DJI Matrice M30T RC Pro controller warned me in a Flashing Red Screen attention getter to descend immediately due to aircraft at similar altitude. I immediately stopped automated mapping mission took manual control and descended immediately to lower than pylons and started a return to take off point. 10 seconds later, only as I was half way back to the take off point did I hear and then immediately see the crop-dusting aircraft which flew about 100 ft. west of my position at a lower altitude than I had been flying the drone at, he was sub 50 ft. AGL. I landed the drone and cancelled my mission for the day. If the Crop Sprayer had not had a transponder (some do not) then I would have not been alerted by my system. Without that alert there was a distinct possibility of him flying under or into my UAS. Crop Sprayers should all have ADS-B so we can avoid them by early notification. When they are transiting low (sub 500 ft.) you cannot hear them or see them until they are very close. It is normal to hear, see, then avoid, I heard nothing today despite being in a quiet environment with little wind.

I was conducting an aerial application flight on a field 17 miles north of ZZZ [Airport]. When I arrived at the field I circled it several times to look for obstacles. While doing this recon, I noticed a truck parked 1/4 mile south of the field. I circled again and noticed that it was an Unmanned Spray Drone operator conducting an application on that field. At the time he had just landed the drone on the back of the truck. I did not see an issue since I would be a 1/4 mile away, and also that I was under the assumption that the drone would stay down low in the field since they were in fact spraying that field. So I proceeded with my application. I flew my field using east/west passes. After about 15-20 minutes I was done but still had to make a trim pass on both ends of the field. Those would be done north/south in this case. I did the west side first, circled around to the North and finished with a southbound pass on the east side of the field. As soon as I pulled up out of the field from that pass, I saw the drone at my 2 o'clock, about 80-100 feet above me, at maybe 1,000 feet horizontally at the most. I abruptly pulled up to further ensure I wouldn't hit it. 

The issue here is that the drone should never have been at that high of an altitude in the first place. A spray drone flies low in the field just like we do, so it should not have been a factor in this case. They are too hard to see until you are very close. I also circled the operator at roughly 300-400 feet AGL several times so they had to know of my presence. If they had any reason to fly the drone that high, they should have waited until I had left the area at the very least. Why they did this, I have no idea but had I have been in a slightly different angle on that pass I would have almost for sure hit the drone. Drone operators should yield to manned vehicles at all times. It should be their responsibility to stay clear and keep separation. I am not exactly sure what needs to be done about this, but low flying pilots of any kind need to remain vigilant.