To stimulate the use of fertilizers, the Central of Georgia Railroad Company announced in 1858 that it would carry all manures for any distance on its line in carload lots at a flat rate of two dollars per ton; and the connecting roads concurred in this policy.

In consequence the Central of Georgia carried nearly two thousand tons of guano in 1859, and more than nine thousand tons in 1860, besides lesser quantities of lime, salt and bone dust.

The superintendent reported that while the rate failed to cover the cost of transportation, the effect in increasing the amount of cotton to be freighted, and in checking emigration, fully compensated the road.[31] A contributor to the _North American Review_ in January, 1861, wrote: "The use of guano is increasing.

The average return for each pound used in the cotton field is estimated to be a pound and a half of cotton; and the planter who could raise but three bales to the hand on twelve acres of exhausted soil has in some instances by this appliance realized ten bales from the same force and area.

In North Carolina guano is reported to accelerate the growth of the plant, and this encourages the culture on the northern border of the cotton-field, where early frosts have proved injurious." [Footnote 30: _American Agriculturist_, III, 283.] [Footnote 31: Central of Georgia Railroad Company _Reports_, 1858-1860.] Widespread interest in agricultural improvement was reported by _DeBow's Review_ in the 'fifties, taking the form partly of local and general fairs, partly of efforts at invention.