The "soil" in this phrase may refer to the earth, nature or grass roots, while "moisture" conveys the meaning of wetness, fertility, richness and comfort. Taken together, "the moist light of soil" may refer to the gift of nature, which nourishes life and provides people with living environment and various resources.
In addition, the word "light" is often used to describe something beautiful, dazzling, bright or eye-catching. Here, "moist light of soil" may also refer to the beauty and importance of nature and its great influence on human life.
Generally speaking, this phrase may praise the beauty and importance of the earth, nature and life, and its influence on human beings.