A famous passage in the Midrash (Bereishit Rabba 31:3) draws a contrast between Noach and Avraham. Noach, the Midrash comments, is first described as an ish tzadik, a "righteous man" (6:9), and then later in life is referred to as an ish ha-adama – "a man of the land" (9:20). Noach's "regression" stands in direct contrast to the progression of Moshe, who early in life is called an ish Mitzri ("Egyptian man" – Shemot 2:19)) and then later an ish ha-Elokim ("man of God" – Devarim 33:1).
This comment by the Midrash clearly works off the assumption that the reference to Noach as an ish ha-adama is a derogatory one, or at least non-complimentary. That Noach earns such a description after having been praised as an ish tzadik is seen by Chazal as expressing a certain demotion in stature. The question arises, how precisely did the Sages understand the term ish ha-adama, and why does it reflect negatively on Noach's character at this point in his life?
The Rosh Yeshiva, Rav Aharon Lichtenstein shlit"a (www.etzion.org.il/vbm/archive/7-sichot/01noach.rtf), explains that Chazal took note of the fact that the Torah chose not to describe Noach as simply an oved ha-adama – "one who works the land." This description of Noach's choice of profession – agriculture – would assuredly not have invited any criticism on the part of the Midrash. The Gemara (Sanhedrin 58b) in fact remarks that "if a person makes himself like a servant to the ground – he will be satiated with bread; otherwise, he will not be satiated with bread." Chazal in a number of contexts emphasize the importance of work and industry and would never have criticized Noach for tilling the land, or viewed such activity as a "fall" from the stature of ish tzadik. However, the Sages insightfully noted that the Torah does not speak of Noach as simply a "worker of the land"; he had rather become an ish ha-adama, a "man of the land." Noach was consumed by his profession to the point where it became part of his very definition, his essential character. Whereas earlier he had been defined primarily in terms of tzidkut, piety and spiritual devotion, at this point he was defined by his work in the field, by the seeds he sowed and the fruits he harvested.
It is in this sense that the Midrash contrasts Noach with Moshe. Moshe was raised as an ish Mitzri, an Egyptian prince, in the capacity of which he was assigned numerous administrative duties. Yet, he managed to live a life characterized by the service of God, and thus he retained his essential definition of ish Elokim. The Midrash thus teaches that regardless of what profession a person pursues or how far he advances in his career, he must always remain an ish ha-Elokim, and always see himself as, first and foremost, a loyal and devoted servant of the Almighty.
In this context the Midrash also comments, "There were three [men] who were emphatically drawn towards the land [=agriculture], but no benefit could be found in them. They are: Kayin, Noach and Uziyahu." Interestingly, the downfalls of these three men, all of whom shared a passion for agriculture, occurred in three different areas. Kayin's failure was irrepressible envy, Noach indulged in wine, and Uziyahu grew arrogant, to the point where he insisted on performing the priestly duties in the Temple. This Midrash perhaps warns of the three possible effects of excessive preoccupation with one's work. First, such preoccupation can lead to competitiveness and the endless race to finish ahead of one's peers, as in the case of Kayin. The story of Noach warns of the tendency to overindulge in the fruits of one's success and thereby lose sight of his religious responsibilities. In the case of Uziyahu, the passion for industrial success led to conceit and an insatiable craving for honor.
It was admirable for Noach to immediately pick up the plowshares and begin cultivating the earth upon exiting the ark. His mission was, indeed, to spearhead the process of the world's reconstruction. Noach is criticized, however, for allowing this process to consume his life and his being to the point where he became essentially an ish ha-adama, rather than an ish tzadik or ish ha-Elokim.