444 IOWA DEPARTMENT OF AGRICULTURE 



If it is not possible to secure well-inoculated soil in the neighbor- 

 hood and it must be shipped or hauled from a distance the use of com- 

 mercial cultures would probably prove cheaper. Satisfactory cultures 

 have recently been placed on the market at a cost of about 50 cents 

 for an amount sufficient for an acre instead of the former price of 

 $2.00, and at such a price they prove less expensive than soil. In large 

 amounts the cost of such cultures is reduced to about 33 cents per acre. 

 With cultures of about equal value with soil available at such a figure, 

 the objections to their use are largely removed. The amount of labor 

 involved in their use is "unquestionably smaller. The cultures are 

 merely mixed with a sugar solution according to directions and poured 

 over the seed, which is then dried over night in a cool dark room and 

 seeded the next day in the usual way. 



Many commercial preparations are now on the market. Unfortunately 

 not all have been fully tested but those which have been tested for 

 efficiency have proven satisfactory. Before employing any new ma- 

 terial, however, farmers are urged to inquire of the Soils Section of the 

 Iowa Agricultural Experiment Station as to its value. Besides the 

 cultures tested in the experiments reported in this bulletin, "Nitragin," 

 "Farmogerm," "Nitrogerm" and the United States Department of Agri- 

 culture culture, the culture of "Legume Bacteria" supplied by the Ed- 

 wards laboratories at Lansing, Michigan, has been tested and proven 

 quite satisfactory. Other cultures are being tested and reports on 

 their efficiency will be available later. Farmers are advised to employ 

 those cultures which may -be secured at the least cost, provided they 

 are recommended here or elsewhere by the* Soils Section. The rela- 

 tive efficiency of the various cultures thus far tested is practically the 

 same for all and a choice can, therefore, only be made on the basis of the 

 expense involved. 



CONDITIONS NECESSABY FOE SUCCESSFUL INOCULATION. 



The inoculation of a legume will not insure a satisfactory crop altho 

 when other conditions are satisfactory for crop growth, it will insure 

 the utilization by the legume of the nitrogen of the atmosphere and 

 consequently conserve the supply in the soil. It will also increase the 

 crop yield and the protein content of the crop. General soil conditions 

 must be satisfactory or inoculation will be unsuccessful and the crop 

 will fail for inoculation will not make up for lack of care in the prepara- 

 tion of the soil, in the choice of seed or in the treatment of the crop. 



The conditions necessary for successful inoculation are the same as 

 those necessary for the successful growth of the legume. The soil 

 must be carefully prepared to insure proper moisture and aeration con- 

 ditions, to correct acidity by the use of lime, to remedy plant food 

 deficiencies by the proper additions and to insure good mechanical 

 condition by the use of manure. Then if the seed has been carefully 

 selected and a legume adapted to the particular soil and climatic con- 

 ditions is chosen, successful inoculation and good crop growth will 

 result. 



When all these conditions are met, then and then only will inocula- 

 tion prove successful. With successful inoculation satifactory growth 



