This is the 12020th most frequent Russian word.
зерновом
"Grain" or "cereal" (adjective, e.g., grain-related).
The word 'зерновом' here modifies 'рынке' to mean 'pertaining to grains', referring to a market where grain products are traded.
На зерновом рынке наблюдается рост цен.
There is a rise in prices in the grain market.
The word 'зерновом' is an adjective describing 'хлебе' to imply that the bread is made from grain or contains grains.
В зерновом хлебе содержится много полезных веществ.
Grain bread contains many beneficial nutrients.
The word 'зерновом' qualifies 'поле', indicating that the field is used for growing grains.