Complex sentence: During Seldon's time Trantor was self sufficient in basic food production however the "later Emperors" (as referenced by "Encyclopedia Galactica") may have badly managed local food production, requiring greater reliance on agricultural worlds for basics.
Split into simpler sentences: During Seldon's time Trantor was self sufficient in basic food production. However, the "later Emperors" (as referenced by "Encyclopedia Galactica") may have badly managed local food production, requiring greater reliance on agricultural worlds for basics.