I suspect that this can work for low intensity farming, like fruits and vegetables, but if you want to feed the cattle of the earth, you'll end up running out of pigeon food.
ps: I recommend we let current humans die of old age, and make less new ones. Not attempt to get rid of humans already here.
Mankind has survived just fine since ancient times without burning anywhere near the amount of fossil fuels burned over, say, the last 200 years.
With wind and solar, we are an the cusp of extremely cheap electricity.
>> is to simply have less people.
Feel free to follow your own advice.