THE MONTHLY BULLETIN. 



401 



The following chart gives the average annual yields of tliree of the 

 seven vegetable crops used in the nitrogen determination made upon 

 various leguminous covercrops. 



TABLE II. 



Soil treatment 



Four-year 

 average 

 shelled 

 com, 

 bushels 

 per acre 



Common vetch 



Barloy plus SIO lbs. nitrate of soda 



Burr clover 



Barley 



Barley plus 270 lbs. nitrate of soda 



Vetcb, v. ervilia 



Barley 



Canadian field peas 



Barley plus 108O lbs. nitrate of soda 



Tangier peas 



Barley 



Melilotus clover 



Barley plus 540 lbs. nitrate of soda 



Fenugreek 



Barley 



Lentils 



Average yield on legume plats 



Average yield on barley plats 



Average increase due to nitrogen added by legumes 



35 

 34 

 35 

 29 

 32 

 38 

 27 

 40 

 41 

 42 

 28 

 46 

 42 

 43 

 35 

 43 



40 

 30 



10 



Two-year 

 average 



potatoes, 

 bushels 

 per acre 



171 

 191 

 228 

 152 

 166 

 231 

 166 

 243 

 218 

 227 

 163 

 252 

 204 

 255 

 164 

 204 



226 



161 



65 



Two-year 



average 



sugar 



beets, tons 



per acre 



15.3 

 16.0 

 17.3 

 13.4 

 12.5 

 16.7 

 10.7 

 17.6 

 17.7 

 20.5 

 12.3 

 19.8 

 15.7 

 16.8 

 12.7 

 19.5 



17.9 

 12.3 



5.6 



Yield Increase by Use of Nitrog-en. 



Average increase in pounds material actually produced on plats 

 receiving nitrogen additions from covercrops or nitrate of soda over 

 the yield of the barley plats. 



Tangier peas 5,763$ 



Melilotus clover (Melilotus iiidica) 5,573 



Parlev plus 1,080 lbs. nitrate soda 4.!Kt8 



Canadian field peas 4,606 



Lentils 3,418 



Burr clover 2,883 



Barley plus 540 lbs. nitrate soda 2,."i03 



Feuusreek 2,454 



Barley plus 810 lbs. nitrate soda 1,779$ 



A'etch. t'. ervilia 1,5S,"» 



Vetch, common, V. satica 992S; 



Barley plus 270 lbs. nitrate soda 402 



jtThese plats lie next the public road and suffer certain losses for this reason and 

 so in reality cannot be compared with the others. 



Use V. ervilia when comparing the vetches with the other legumes as 

 to their effect on the crop following. 



From these charts one can easily see the increases in the yields of 

 the field crops on the legume plats over those on which barley was 

 grown. This increase could only be due to the nitrogen added by the 

 vetches, peas, etc., as the actual organic material turned under was as 

 great on the barley plats as on those growing legumes. 



Another proof of this statement lies in the fact that the barley plats 

 required large additions of nitrogen to bring up the yield of the crops 

 following to the standard of those plats where legumes had been grown 

 and incorporated into the soil. 

 3—13194 



