an acre is about 70 yards by 70 yards in a square, there are online calculators that will get you exact numbers if you care to use one
https://www.checkyourmath.com/conver...ards_acres.php


MY guess off top of my head and or how I would buy seed and lime and such, would be call it a MIN of a 1/4 acre there and go from there
as most all first time plots need more lime and seed and such the first time, to get a good take, as many seeds and such don;t grow right,a s LIME and PH levels are never corrected!

something to consider is, the SOONER you get the lime down the better, and you really DON"T Need to PLOW The site, just scuff the soil up to mix in the lime with the dirt, and again sooner done the better lime is a SLOW working deal to change any PH levels! your seed and fertilizer add at time of planting!