ILLINOIS
Prof. C. G. Hopkins, Agronomist Illinois experiment station.—Alfalfa is being introduced into Illinois to a considerable extent. Very careful and somewhat extensive investigations conducted by the experiment station, beginning in 1901, have positively established the fact that alfalfa can be grown in this state on several of our most abundant types of soil. As a rule, it is markedly advantageous to thoroughly inoculate the soil with alfalfa bacteria, preferably by taking infected soil from a well-established alfalfa field, where root tubercles are found in abundance or from land where Sweet clover (melilotus), has been growing successfully for several years. Infected Sweet clover soil serves just as well as infected alfalfa soil for the inoculation of alfalfa fields. As a rule, the best results are secured from summer seeding. The land should be thoroughly prepared and made as free from weeds and foul grass as possible and then seeded between June 15 and August 15, if the conditions are favorable. Under exceptional conditions good results are obtained from earlier and later seeding. Three cuttings are usually obtained in the northern part of the state and four in the southern part. The average yield is five or six tons per acre. A liberal use of farm manure in getting the alfalfa started is advantageous and on some soils the application of lime is necessary in order to correct the acidity of the soil. As a rule, the yield is increased by adding to the soil some form of phosphorous. A yield of 81⁄2 tons of thoroughly air-dry hay has been obtained where a special effort has been made to make the conditions favorable.