There was a discussion almost 3 years ago regarding drones, that are able to plant 36K trees per day. There was also a reference to the 1970s planting machines,

There was a discussion almost 3 years ago regarding drones, that are able to plant 36K trees per day. There was also a reference to the 1970s planting machines, that are much simple in mechanical design and are able to plant 10-20K trees per hour. https://news.ycombinator.com/item?id=9444521 https://news.ycombinator.com/item?id=9444521