The farmer is instructed to bring the first fruits of his fields to the Bet Hamikdash and give them as an offering to Hashem. At the time he offers them he is to recite an entire passage in which he relates the history of the Jews and the travails Yaakov had when he lived with Lavan. We perform many Mitzvot and there were many occasions that the Jew had to bring offerings to the Bet Hamikdash. He is never told to recite this history. Why specifically with relation to the first fruits the farmer produces in his land does he have to make this declaration?
We know that Chazal were very concerned that everyone feel obligated to develop the Land of Israel. The famous story of Chazal is known to all about an elderly gentleman who was seen planting trees and was asked why he was doing so. Certainly, because of his age, he will not be around to enjoy the fruits of his labor. His answer was that he has to cultivate the land for others just as those who came before him did for him.
This was the problem that faced Yaakov when he lived with Lavan. He was not able to cultivate the Land of Israel. This is what Rashi meant when he explained what Yaakov said to his brother Esav when he returned to Israel. Yaakov says that he has oxen and donkeys. Rashi comments there that he explained to his brother that the blessing from his father was that he will have the good fortunes of the dew of the heavens and the fat of the land and he had neither. The point he was making was that living with Lavan he became rich but he had no share in developing the Land of Israel.
It is exactly at the time the farmer brings his first fruit as an offering he thanks Hashem for making it possible for him to fulfill the great Mitzvah of developing the land and not be like Yaakov was when he lived with Lavan.