From Wikipedia "Heavy crop production rapidly depletes the soil of potassium, and this can be remedied with agricultural fertilizers containing potassium, accounting for 95% of global potassium chemical production". ---For this to replace lipo yeah there would need to be a BIG a shift
You would need to consider altered flight characteristics and maybe reduced flight range with the addition. Might act as a sail and just drag any drone around enough as to render it useless. Also, what would a 4ft flying panel look like on radar.