Treefarm

turtle.select(1)
function cutTree()
    turtle.select(2)
    turtle.dig()
    turtle.forward()
    turtle.digDown()
    while turtle.detectUp() do
        if turtle.detect() then
            for i=1,4 do
                turtle.dig()
                turtle.turnLeft()
            end
        end
        turtle.digUp()
        turtle.up()
    end
    while not turtle.detectDown() do
        turtle.down()
    end
    turtle.back()
    turtle.select(1)
    loop()
end

function checkGrowth()
    turtle.up()
    if turtle.detect() then
        cutTree()
    else
        turtle.down()
    end
end

function loop()
    if not turtle.detect() then
        turtle.place()
    end
    checkGrowth()
    sleep(10)
    loop()
end

loop()