174 



The fcrtiliziiiix ('HVct of tlic stnbhlc a« shown hy the 

 second cro]) of corn is nnicli h\ss than the increment 

 line to tin* vines ]>h>\\(Ml under niJiny niontlis before. 



There is a sixlh lest with corn noi heh)U<;ing in tlie 

 ])rec(Mlinir table, that iiivcs additioinil- <b'ita for a com- 

 parison of the second-year effects of vines with stnbble. 

 Condanin^ the resnlt-s of the six tests, we find that the 

 corn grown as the second crop after legnmes atfoixled 

 a larger yield on the vine plots than on the stubble plots 

 to the average extent of 2.1 bushels per acre, or 14 per 

 cent. 



Tni: DruATiox or the Fertilizing Effects of Stub- 

 ble AND Vines of Cowfeas and Velvet Beans. 



The stubble of these legumes repeatedly exerted so 

 slight an effect on corn grown as the Siecond crop, (an 

 average of only one and one-third bushels per acre), 

 that we may reasonably conclude that two crops mark 

 the limit to which the benefits of lei»unie stubble ex- 

 tends in cases where the soil is sandy and permeable, 

 as at Auburn. It is quite possible that the advantages 

 from u-sing stubble as fertilizer might have been slightly 

 more enduring in a stiff er soil, but in no case can such 

 a relatively small amount of vegetable matter and nitro- 

 gen afforded by the roots and stubble influence the suc- 

 ceeding crops more than a few" years. 



It is quite a different matter Avlien the ^ines, repre- 

 senting the entire gi'owth of the legume (except in some 

 cases the pods) are plowed under. We have learned 

 from the data in previous tables that the yield where 

 the vines were used as fertilizer was in the first crop, 

 03 to 189 per cent, greater than the yield of the corre- 

 sponding crop immediately preceded by a non-legum- 

 enous plant; and that in the second crop the increase 



