原文是这样的：

While she is confident they will succeed, shi lists farming's many challeges: ".You don't often get a day off.Supermarkets put a lot of pressure on farmers to keep price down. With fewer people working on farms it can be isolating." she said.

主人公she罗列从事农业所面临的困境/挑战。所以it指代的是farming。

一个代词指代的对象通常在句子的上下文中。如果你截取的部分太少，可能就会导致代词的指代不明。