Moon is the source of food grains.

Soma, the predominating deity of the moon, is the source of food grains and therefore the source of strength even for the celestial beings, the demigods. He is the vital force for all vegetation. Unfortunately, modern so-called scientists, who do not fully understand the moon, describe the moon as being full of deserts. Since the moon is the source for our vegetation, how can the moon be a desert? The moonshine is the vital force for all vegetation, and therefore we cannot possibly accept that the moon is a desert. As stated by learned scholars, the moon is the mind of the Supreme Personality of Godhead. May that Supreme Personality of Godhead, the source of all opulences, be pleased with us.

Source: A.C. Bhaktivedanta Swami Prabhupada (2014 edition), “Srimad Bhagavatam”, Eighth Canto, Chapter 5 – Text 34