Interpretations of Results Noted in Experiments upon Cereal Cropping Methods after Soil Sterilization.

It is not my intention at this time to give the details of extended experiments upon soil sterilization and its effects; nor to enter any special criticisms upon the work of other investigators. I wish only to call attention to some facts, observations, and conditions of the work centered about cereal cropping, and experiments upon soils which may indicate that a new light may be thrown upon the conclusions to be drawn ;-with that light emanating from a different source than has usually been indicated by most experimenters. Obscrvatioizs a i d XcfEcctioizs.-The following features of cropping and experiments will be familiarly known to most of you: I. New lands, when first sown to wheat or other cereals, produce quite lavishly in seed of high quality and at slight effort on the part of the farmer. These new land yields, in this country, are quite commonly taken as the standard of what ought to be expected. 2. It is a common experience that as soon as a particular cereal crop has become general, and that usually follows in a very few years, a marked deterioration, botl; in yield and quality, sets in. The crop, except in special years, and under rare exceptions of special farming, seldom again reaches the same high grade of yield and quality. Indeed, the yield generally falls to the average for the country, above which it can be raised again only through exceptional methods ; and, to the chagrin of many of our most able agricultural educators, no philosophy of cropping or land improvement seems to give the farmer the desired results with any regularity, year by year, for any long period of time. The crop or variety once a favorite in a locality usually has a short life and finally gives place to a real change in agriculture, seldom, if ever, to regain its place. 3. Not many theories have been advanced to account for these results. The chemist and his followers have usually directed thought in the matter, and agriculturists, generally, have taken the chemist's '. dictum that marked changes have occurred in the balance of plant food relations of the soil, thus accounting for the rapid first deterioration of the crop through chemical losses noticed in the soil. Thus if a lack of proteid is found in the grain of wheat and a loss of nitrogen is observed in the soil, it has …