MrKMG Tree

local saplings = 1 -- the slot where the saplings are
turtle.select(saplings) -- select the saplings
while true do
    turtle.turnLeft()
    turtle.suck()
    turtle.turnRight()
    turtle.select(2)
    turtle.drop()
    turtle.select(saplings)
    if turtle.getFuelLevel() < 4000
    then
        turtle.turnLeft()
        turtle.turnLeft()
        turtle.select(9)
        turtle.suck()
        turtle.refuel(64)
        turtle.select(saplings)
        turtle.turnRight()
        turtle.turnRight()
    end
    for i = 1, 9 do -- plant 8 saplings in a row
        turtle.turnRight()
        if not turtle.compare() then -- if not a sapling, then a tree grew
            turtle.dig()
            turtle.forward()
            while turtle.detectUp() do -- dig tree out
                turtle.digUp()
                turtle.up()
            end
            while not turtle.detectDown() do -- back down to ground
                turtle.down()
            end
            turtle.back()
            turtle.place() -- put down new sapling
        end
        turtle.turnLeft()
        turtle.forward()
    end
    -- turn around and line up for next pass
    turtle.turnLeft()
    turtle.turnLeft()
    turtle.forward()
    turtle.forward()
    turtle.forward()
    turtle.forward()
    turtle.forward()
    turtle.forward()
    turtle.forward()
    turtle.forward()
    turtle.forward()
    turtle.turnLeft()
    turtle.turnLeft()
    os.sleep(30) -- sleep for 30 seconds to allow trees to grow
end