the.com/wheat belt

means The broad climatic band of semi-arid grassland regions around the world — ideal for wheat because it gets just enough rain to grow the crop but too little for most other agriculture.

from A straightforward compound from English, 'wheat' (the ancient grain, its own name tracing back to a root meaning 'white,' for the pale flour it makes) plus 'belt' used in its geographic sense of a broad zone or band — the same sense found in 'corn belt' or 'rust belt.' The term emerged alongside large-scale agricultural mapping, as settlers and surveyors noticed wheat farming clustering in specific rainfall zones across places like the American Great Plains, the Canadian Prairies, Ukraine, and Western Australia.