That's so sweet, and the characterizations are dead on. I especially liked it seeming to Atrus that Yeesha *was* a baby only a day ago.

The only minor change I'd suggest is to the very last line: saying that an Age needs lima beans is a bit specific and precise. Maybe something like, "Lima beans, I grumble mentally. Beans yes, the soil needs a nitrogen fixer if this ecosystem is going to work.
But it's a wonderful story. How *do* you explain such complex concepts and, really, ethical issues to a small child with dirt on her nose?