The influence of two years of bare fallow on the fertility of light land exhausted by continuous cropping with wheat or barley for fifty years has been very great, the immediate result being an increase in the crop of wheat by 50% and of barley by 140% over the average yield of the unmanured plots for the ten years before the fallow was taken. A repetition of the fallow after a further period of five years of continuous cropping without manure gave a very similar result.

Whatever had been the treatment of the land during the fifty years before the fallowing, the yield produced as a result of the bare fallow fell off very rapidly in the succeeding years, when no further manuring was given. In fact, after the first two or, at most, three years the crop, of grain went much lower than it had been before any fallowing had taken place. This falling off in yield was almost equally felt on plots which had been treated with artificial manures during the preceding fifty years as on those which had been unmanured throughout.