The sentences “The Philippines is
agriculturally rich” and “The Philippines is rich
agriculturally” means exactly the same thing. Generally, adverbs can move around rather freely in a sentence; in particular, “agriculturally” as an adverb of manner has the flexibility to be positioned before or after the adjective that it modifies, which in this case is “rich.” It can even be positioned up front to modify the entire clause, “
Agriculturally, the Philippines is rich,” or as a parenthetical afterthought, “The Philippines is rich
, agriculturally” (take note of the comma after the clause). Ultimately, though, the writer has to decide which of the possible positions of the adverb will provide the desired emphasis in modification.
For a comprehensive discussion of adverbs and their positioning in sentences, click this link to
the CCC Guide to Grammar and Writing.