We farm also. Believe it or not, I don’t remember when we sampled soil. (at changing of the guard phase from my father)
Our farms are all dry land, except for one that my brother owns.
We have most of our fields grid-sampled at least every other year (so we are probably doing half of them a year), and then the needed lime and/or nutrients are applied with a TerraGator that is using the GPS grids. Parts of the field may require a ton of lime, while another may require none. The computer handles it all.
Liquid nitrogen is knifed-in on corn and cotton in the required amounts around 2-3 weeks post-emergence.