Carissa sure is bringing in a lot of complicated infrastructure here! All this talk of 'pay'. It would take a very great genius indeed to invent an infrastructure as complicated as this sounds, and bring it in as the best solution to the current problem about farming and slacking.
If Keltham tries to extract just the useful part of this solution, it sounds like Carissa is saying that everybody should be assigned their own particular plot of land, to farm, and then we look at whether somebody's grain yields passed a certain minimum threshold, and people under that threshold get kicked out and don't get to eat. This is better because everybody can see whether a worked did enough work, or not, and so we don't have the same problem with false accusations of slacking.