Indeed, what is up with this title? The poem has nothing to do with farm implements, rutabagas, or any landscape apart from a shoebox apartment. Let's start with the basics. "Farm implements" refers to any of the wide variety tools that might be used for farming, like a shovel, hoe, or tractor. A rutabaga is a root vegetable also known as a Swedish or yellow turnip. It is, to be sure, an obscure, dare we say cartoonish, vegetable. You probably don't eat them often, if at all. Ashbery knows all this.
A few more things. First, the six words that are repeated most throughout the poem seem to suggest the difference between rural and city life: "thunder," "apartment," "country," "pleasant," "scratched," and "spinach." The poem is set in the city, but the title refers to the country. Second, the characters in the Popeye cartoon have close relations with various foods: Popeye loves spinach, Wimpy loves hamburgers, Swee'pea and Olive Oyl are named after agricultural products. Third, "Farm Implements and Rutabagas in a Landscape" is a parody of a title that a painter would give to a landscape painting. Ashbery loved painting and was once employed as an art critic. Many of the best landscape European landscape painters came from Northern Europe – places like Belgium and the Netherlands – where people might actually farm and eat rutabagas. Thus, the poem is a kind of painting in words.
Finally, and most importantly, "Farm Implements and Rutabagas in a Landscape" sounds both silly and interesting. Don't discount the silliness factor – it's very important to Ashbery. His motto could be: if it sounds good, write it.