I am assuming it is this part...
Mark of Altruism
There is a farmer, according to the Hermit, who is in need of a hero. The farmer, who will bear the title Moisture Farmer, spawns in a broad area south of Mos Taike. Although he doesn't appear on the radar he will appear on the overhead map, so make sure it's enabled. The farmer has been found in the areas near these locations:
2168 1293
2488 1676
1839 966
2570 1164
2478 687
1003 1240
2123 1291
2470 1394
2511 1357
2439 1294
3196 1272
3303 1107
2123 1291
2494 1714
2545 1741
2778 1507
5100 800
2560 1324
2437 1421
3640 -44