flag = 0
function turn()
 if flag % 4 == 1 then
  turtle.turnLeft()
 else
  turtle.turnRight()
 end
end
function check()
 for i=1,16 do
  value = turtle.getItemDetail(i)
  if value and value.name == "Forestry:soil" then
   turtle.select(i)
   return true
  end
 end
end
while check() do
 status, value = turtle.inspectDown()
 if value.name == "Forestry:soil" and value.metadata == 13 then
  turtle.digDown()
  turtle.placeDown()
 else
  if turtle.forward() then
   sleep(1.5)
   if flag % 2 == 1 then
    turn()
    flag = flag + 1
   end
  else
   if flag % 2 == 0 then
    flag = flag + 1
    turn()
   else
    status, value = turtle.inspect()
    if value and value.name == "minecraft:obsidian" then
     sleep(120)
     for i=1,16 do
      turtle.select(i)
      turtle.refuel()
     end
    end
    turtle.turnRight()
    turtle.turnRight()
    flag = flag + 1
   end
  end
 end
end