FERTILIZING VALUE OF HAIRY VETCH. 



3 



as those inoculated at the start, and the difference was still noticeable 

 after three months' growth (December 11, 1907, to March 19, 1908). 



Rye was grown under the same conditions but did not make a very 

 good growth. Plants were taken off for weighing when flowers began 

 to appear, and samples from each lot were analyzed. The results are 

 shown in the following table: 



Table 1.— Results of greenhouse tests of rye and inoculated and uninoculated 



hairy vetch. 



Two pots, containing twenty 

 plants. 



Green weight. 



Dry weight. 



Nitrogen. 



Total nitrogen 



furnished by 



plants. 



Hairy vetch, control plants 



Hairy vetch, inoculated plants 



Rye . - - -. 



Gra/tns. 



148.5 



2;5.5 

 72 



Grams. 



25 

 44 

 16 



Per cent. 



3.41 

 3.49 

 1.69 



Grams. 



0.82 

 1.33 

 0.27 







It will be seen that even when partial inoculation of the vetch took 

 place the highest results both as to yield and percentage of nitrogen 

 were obtained when artificial inoculation was practiced and that both 

 lots of the legume were superior to rye in furnishing nitrogen. 



As a check against chance inoculation, a few small pots of the same soil 

 as that used in the greenhouse test were sterilized by autoclaving for 1 

 hour at 140° C, part of them being planted with inoculated vetch seed. 

 The pots were kept in a glass cage, carefully protected against insects 

 or dust infection, and were watered with sterile distilled water. The 

 checks remained free of nodules throughout the experiment, while those 

 inoculated were plentifully supplied with nodules. The soils were so 

 injured by the heating that neither set of plants made a normal growth, 

 their chief difference being in color. The check plants were pale green, 

 while the inoculated plants were healthy in color. 



NITROGEN FURNISHED BY HAIRY VETCH TURNED UNDER. 



If the percentages shown in Table I are taken as representing the 

 nitrogen content of the field-grown vetch previously mentioned, it will 

 be seen what an enormous gain was effected by abundant inoculation. 

 Assuming one-fifth of the green weight to represent the dry weight of 

 the vetch, the following amounts of nitrogen were furnished on the 

 cover-crop plats at Hockanum, Conn.: 



Table 11.— Comparison of nitrogen in cover crops of rye and inoculated and unin- 

 oculated hairy vetch grown at Hockanum, Conn. 



Plat. 



Green weight, 

 per acre. 



Dry weight, 

 per acre. 



Nitrogen. 



Hairy vetch. Inoculated 



Pounds. 

 14,400 

 4,240 

 14,720 



Pounds. 



848 

 2,944 



Per cent 



3.49 

 3.41 

 l.€9 



Pounds per a'-re. 

 100.51 



Hairy vetchj uninoculated 



Rye ... 



28.91 



49.75 







