Mary's, for the purpose of hiring them out in the cane fields.

玛丽的，目的是在甘蔗田里雇用他们。

My first job was to drive the oxen that plowed the cane fields.

我的第一份工作是赶牛在甘蔗田里耕作。

Sugar cane seems to be controversial. It doesn't require as much fertilizer as corn does to grow, but when they burn the sugar cane fields, that releases loads of greenhouse gases.

甘蔗看上去很有争议。它不如玉米生长需要那么多肥料，但在烧甘蔗田时，会放出大量温室气体。