Complex sentence: The prefecture also boasts Japan's second-highest agricultural output: among all the prefectures, only Hokkaidō produces more agricultural products, and Chiba leads Hokkaidō in vegetable production.
Split into simpler sentences: The prefecture also boasts Japan's second-highest agricultural output. Among all the prefectures, only Hokkaidō produces more agricultural products, and Chiba leads Hokkaidō in vegetable production.