Complex sentence: Sichuan in the Middle Ages welcomed Near Eastern crops, such as broad beans, sesame, and walnuts, and starting in the 16th century its list of major crops was lengthened by New World newcomers.
Split into simpler sentences: Sichuan in the Middle Ages welcomed Near Eastern crops, such as broad beans, sesame, and walnuts. Since the 16th century, the list of major crops in Sichuan has even been lengthened by New World newcomers.