《旧唐书·列传·卷六十八》
原州虽然降霜早，不能种粮食，但在其东面有平凉，只需一个县耕种，就可以足够吃了。
原州虽早霜，黍稷不艺，而有平凉附其东，独耕一县，可以足食。
Although frost falls early in Yuanzhou and it couldn't yield harvest, there was Pingliang to its east. As long as one county produced crops, that would be enough food.