The game tells me I can get ribbons for fertilizing my neighbors’ crops. Anyone figured out how to do that?

when i look at my ribbons the last one says fertilize 100 neighbors crops, how do i do that?

I was helping my neighbors farm and some of their crops were sparkling…what is it!?

Thanks!
ps dont make fun cause I play farmville

Whenever I harvest my crops that have been fertilized by my neighbors on farmville I don’t get ANY money or XP, can anyone tell me why or if this is normal? Thanks!