Eventually, they get oxen to work the fields, and they're able to plow quite huge areas. Their income from selling the rice lets them buy lots of things: food and spices, books, decorations for their homes, and even getting a fireplace for their home, so there isn't quite so much indoor smoke. As more and more draft animals and modern agricultural tools get put to use, and the pay of those working in factories rise, more and more people leave for the cities, leaving those still farming with ever more land for them to cultivate, with animals doing most of the heavy lifting.
Decades pass, with life constantly getting better decade after decade. The protagonist is now a grandmother, but still working on the farm that now stretches over vast acres. She's not in the best of health, so the oppressive heat could be dangerous; she's never outside one of her air-conditioned harvesting machines for more than a few minutes, always in her special ultra-breathable cooling dress. Today she's chosen to drive down to the city, a metropolis of sprawling skyscrapers and beautiful parks, to meet her granddaughter who's just given birth, and is resting with her baby inside a private room larger than her childhood home. There are nurses everywhere as she visits the towering maternity care center, there to help the new mothers and their babies.
The movie ends with her driving her daughter back to her childhood home, now a multi-story mansion surrounded by a beautiful garden of bright green grass. The camera gets a look at the graves of her brother and father, now covered with offerings of food they never got the chance to enjoy, before showing us a view of her mother resting peacefully inside of a cryonics center, a pleased expression on her face at the prospect of seeing her daughter again.