Don't Like Chickens, Love Their Manure

That was my feeling growing up, at least as far as liking chickens goes.  Turns out one study shows their manure improves cotton yields over chemical fertilizer because it conditions soil.

In their study, Tewolde and colleagues figured the litter's value as a soil conditioner as an extra $17 per ton of litter. They calculated this by balancing the price tag of the nutrients in litter with its resulting higher yields, a reflection of its soil conditioning benefits.
They found that cotton yields peaked 12 percent higher with organic fertilizers, compared to peak yields with synthetic fertilizers. With all benefits factored in, they found that chicken litter has a value of about $78 a ton, compared to $61 a ton when figured by the traditional method.

This isn't organic farming, per se, but it's close.