A Famous Plot Again, there is a yet more famous
plot which has grown wheat in continuous succession for eighty years or so without any manure. It still produces a crop (said to be nearly equal to the world's average), and a sort of dead level seems to have been reached. The crop no longer perceptibly diminishes, though there is an accentuation of the struggle with weeds (especially, I think, black bent) ; and on this little Hertford-
shire plot under the eye and control of the best of research- workers, are compacted a number of the problen- s that face the cultivators of the once virgin soils of the prairie provinces
of Canada. There, too, the weeds arc a more present enemy than the exhaustion of the soil. How the soil recovers its fertility, becomes a widow's cruse, is one of the most essential of agricultural secrets, and has been more deeply penetrated at Rothamsted than anywhere else, largely because the expe- riment has been much longer and more continuous than elsewhere. The best friend of the farmer struggling with weeds on the Alberta plains is the Rothamsted plot.