Forget the Apocalypse, I Farm Now!

Ryan Lynch came out of a world overrun by the dead and woke up in an ancient village, in the body of a young farmer everyone took for an idiot. The mother in that house was blind and had no one else, and the village had already chosen the young man to be offered up in a sacrifice. He had a phone with an AI on it and a stock of supplies from his own time. He used both to get clear of the sacrifice and then to handle the men who ran the village. He went after a band of mountain bandits and found his own older brother among them, separated from the family years before. He took on his brother's debt and needed money for it, so he put future methods into the fields, opened new ground with the villagers, and got the grain shortage under control. He also met a princess who had fallen on hard times, and the two of them went after corrupt officials and the merchants working with them. A doctor came through from the future after that, bringing rice seed that grows fast enough to feed hundreds of thousands. The seed arrived along with a virus of the kind Ryan had left behind, which the doctor had not meant to carry, and it got loose.