24 FARM PRACTICE WITH FORAGE CROPS IN OREGON, ETC. 



and plow it under 8 to 10 inches deep. In the spring, when the land is in good 

 working condition, cut it up thoroughly with a disk harrow and work it down 

 fine. Let it lie for a week or ten days ; then give a good harrowing so as to 

 destroy all weeds. Sow about 15 pounds of clean seed per acre and cover with 

 a harrow. If the soil is inclined to be dry, finish with a roller. About the time 

 the seed is sown, put on 75 to 100 pounds of land plaster to the acre." 



INOCULATION. 



The failure of alfalfa west of the Cascade Mountains is frequently 

 due to the lack of nodule-forming bacteria in the soil. If the land to 

 be sown has never grown alfalfa before, it is the safest plan to arti- 

 ficially introduce these organisms. This may be done in two ways : 



(1) From 800 to 500 pounds of soil, the more the better, may be 

 hauled from a field that has recently produced alfalfa Avith nodules 

 on the roots, and scattered evenly over the surface of the new field. 

 This should be done just before the alfalfa seed is sown and the soil 

 should be thoroughly mixed with that of the new field b}^ harrowing 

 or disking. It is quite expensive to inoculate large fields in this way 

 and there is always a possibility of transferring plant diseases from 

 one field to another. 



Of scarcely less importance is the danger of disseminating noxious weeds 

 and insect pests through this plan of inoculating by means of natural soils. 

 Even though weeds may not have been serious in the first field, the great number 

 of dormant seeds requiring but a slight change in surroundings to produce ger- 

 mination is always a menace. If soil is to be used, however, whether obtained 

 from near-by fields or shipped long distances, the evidence should be clear that 

 the soil is free from the objections mentioned above.^ 



(2) Pure cultures of the proper bacteria may be used. The Bureau 

 of Plant Industry of the United States Department of Agriculture 

 has isolated the different organisms for the different legumes, is 

 growing them in pure cultures, and furnishes them to farmers whose 

 soil conditions seem to indicate that inoculation is necessary. 



Those desiring inoculating material should write to Soil Bacteri- 

 ology Investigations, Bureau of Plant Industry, Washington, D. C, 

 for an application blank. To avoid delays, requests should be on 

 file several weeks before the material is to be used. 



Should weeds tend to crowd out the alfalfa during the first year, 

 they should be mown often enough to hold them in check. The cutter 

 bar of the mower should be set about 5 inches high in order that the 

 young alfalfa plants may not be cut too closely. If the crop mowed 

 would be sufficient when dry to make a third of a ton or more of hay 

 (and dried weeds) to the acre, which it usually will be in spots, it 

 should be removed from the field; if less than this it may be per- 

 mitted to lie where it is cut. 



a Dr. James Withycombe, in Bulletin 7(3, Oregon E.xperiment Station. 

 6 Farmers' Bulletin No. 240, U. S. Dept. of Agriculture. 

 94 



