there is no indication in OED that the similarity to circulation is other than happenstance.

sarculate [f. ppl. stem of late L. sarculre, f. sarculum (see SARCLE).]

trans. To hoe. So sarculation rare, hoeing.

1623 COCKERAM, Sarculate, to weed. Sarculation, a weeding. 1733 TULL Horse-Hoeing Husb. vii. 62 Their Sarculation was used but amongst small Quantities of sown Corn.


speaking of happenstance, the wwftd theme this week appears to be words that sound like something that they really aren't; but on second thought...
http://home.mn.rr.com/wwftd/

btw, sarcle is a hoe; to sarcle is to weed with a hoe, or sarculate.

where did you dig this one up, Wordgrub?