Is there any scientific explanation for the Sabbath Year?

> For six years sow your fields, and for six years prune your vineyards > and gather their crops. But in the seventh year the land is to have a > year of sabbath rest, a sabbath to the Lord. Do not sow your fields or > prune your vineyards. *(Leviticus 25:3-4, NIV)* Is there any scientific reason why God commanded them to let the land take a rest every 7 years? Will it increase the fertility of the land? If so, please provide some scientific research on this.