Source: Tafsir al-Ahlam al-Kabir (Ibn Sirin)
The farmer in a dream is a man who strives in the affairs of the world and the Hereafter, diligent in his work. Seeing him indicates fertility and sustenance.
Source: Ta'tir al-Anam fi Ta'bir al-Manam (Al-Nabulsi)
The farmer indicates striving and diligence in work. His plowing of the land indicates marriage for the unmarried, and pregnancy for the married.
Source: Al-Isharat fi Ilm al-Ibarat (Ibn Shahin)
The farmer is interpreted as a blessed man who brings goodness and benefit. Seeing him indicates a year full of goodness and blessing.