Feeding back means that when an old crow is old and can't fly, a little crow feeds her mother with food, just like a mother bird feeds a bird. So it is called "feedback". Now it is used to describe "repaying parents".
So this is a poem about going home during the Spring Festival: this heavy snow has hindered my trip, and I am afraid that I will delay going home and I will not be able to repay my parents' kindness!