Verse 5 underscores that the translation of the Book of Mormon was not only into English, but that it was a translation that converted certain concepts, as well as words, from one language to another. Verse 5 invokes a very specific agricultural metaphor that can be found in Revelation 14:15: “And another angel came out of the temple, crying with a loud voice to him that sat on the cloud, Thrust in thy sickle, and reap: for the time is come for thee to reap; for the harvest of the earth is ripe.”
This is an image that relates to a people very familiar with the harvesting of grain, and certainly by Joseph Smith’s time would have been comparable to the harvesting of wheat. Neither that grain, nor the sickle used to harvest it, was part of New World agricultural activities. There existed an important maize (type of grain) crop, but sickles were not used. Even the verb “harrowed up” refers to an implement that turns over the soil. While that is a powerful image, it was not available to the original writers of the Book of Mormon. What that means is that, in addition to giving us a text in English, the Book of Mormon converted cultural metaphors into language that would be understood by modern readers, rather than replicate a metaphor that the original writers might have understood, but which would have less meaning for the modern audience for whom it was translated. This is not an unusual feature of some styles of translation.
Nevertheless, the idea that wheat, or even maize, might be beaten down by storms is a very understandable metaphor for both ancient writers and modern readers.