“ The recognition that continuous growing of wheat on the same area of land robs the soil of its fertility was universal among ancient peoples, and the practice of “fallowing” or resting the soil is as old as agriculture itself. ”

“ Improvements in crop rotations and manuring have diminished the necessity of the “bare fallow,” which is uneconomical because the land is left unproductive, and because the nitrates in the soil unintercepted by the roots of plants are washed away in the drainage waters. At the present time bare fallowing is, in general, only advisable on stiff soils and in dry climates. ”