I think this is going to be a hard one to discover, but I am hoping that someone will be able to help.
From what I remember, the movie takes place in a small town in Central America, and the family's crops will not grow. There is some importance of the moon and the main character, maybe some relation to the harvest. Later on the family gets other towns people to help them dig a hole in their backyard where something is discovered. Shortly after they are visited by aliens in a large UFO. I can't really remember much else from the movie. Part of me wants to say their was a native man who was a close friend to the family and played a role with the main character who was either an older child or young adult.
It's probably been somewhere between 15-20 years since I have seen this movie.