What is the best way to read a file into R when the header has two necessary lines for the header?

This happens to me all the time, as people often use one line for the column name and then include another line underneath it for the unit of measurement. I don't want to skip anything. I want the names and the units to carry through.

Here is what a [typical file with two headers might look like](https://www.dropbox.com/s/9328klp413xej8g/data.txt):

```
trt   biomass    yield
crop    Mg/ha    bu/ac
C2      17.76   205.92
C2      17.96   207.86
CC      17.72   197.22
CC      18.42   205.20
CCW     18.15   200.51
CCW     17.45   190.59
P       3.09    0.00
P       3.34    0.00
S2      5.13    49.68
S2      5.36    49.72

```