http://www.buzzle.com/articles/why-we-throw-rice-at-weddings-other-nuptial-origins-revealed.html

But the reason it is thrown at weddings is because it symbolizes life and fertility, and just because of the fact that it is a tradition.

NOTE: Here’s a old urban legend about this practice…. in recent times some new generation environmentalists tried to ban this custom because it said that birds would eat the uncooked rice then it would swell up in their stomach and kill them…… ha ha ha what do they think birds eat in the wild? ha ha …you ever see a bird cooking his food?

She’s the one on her hands and knees picking up the rice!