Decomposition of Sweet Clover as a Green Manure 123 



four of the American experiment stations. The habits, soil adaptations, 

 and agricultural value of the plant are discussed. It is concluded that 

 the plant is peculiarly suited to adverse conditions, that it will thrive 

 where other legumes will not, and that as a green manure it adds more 

 humus-forming material to the soil than do any of the other nitrogen- 

 gathering plants. Lloyd states further that the best growth is secured 

 in soils rich in lime, and that inoculation with the appropriate bacteria 

 may be necessary. 



Investigations to test the manurial value of sweet clover have been 

 limited to a study of its effect on a succeeding crop. Orth (1892) con- 

 ducted an experiment to note its effect as a green manure on succeeding 

 crops of oats and potatoes. In May sweet clover was sown in rye, and 

 in the summer of the following year the crop was plowed under. The 

 yield of potatoes was doubled in comparison with that of check plats 

 which received no green manure. Better yields were secured where sweet 

 clover was turned under than on similar plats which received eight tons 

 of stable manure instead of green manure. The yield of oats, grain and 

 straw, was increased by 60 per cent and 90 per cent, respectively. Green- 

 manuring with sweet clover also increased the growth of maize. 



Westgate and Vinall (1912:30) describe an experiment conducted in 

 Alabama showing the effect of sweet clover on a succeeding corn crop. 

 On poor, run-down soil, 6672 pounds of sweet clover hay per acre were 

 produced the first year and 7048 pounds the second year. The stubble 

 was then plowed under and the field was planted to corn, 22.7 bushels 

 per acre being produced as compared with 16.2 bushels where sweet 

 clover had not been sown. 



Hopkins (1910:219-220) mentions some Illinois investigations with 

 sweet clover regarding yield and nitrogen content at the end of the 

 second season's growth. Figures are given for roots and tops separately, 

 showing 86 per cent of the total nitrogen to be present in the latter. 

 It is concluded from the results obtained that sweet clover gives great 

 promise as a green-manure crop. 



The bibliographical evidence indicates that sweet clover thrives under 

 a great variety of soil and climatic conditions, and that it is peculiarly 

 adapted to adverse situations. Data regarding yield and nitrogen content 

 show that the plant compares favorably with the other legumes in its 

 ability to fix nitrogen. Further, surveys indicate that good stands have 

 been obtained where other legumes have failed. In view of all this 

 evidence in favor of sweet clover, it is pertinent to ask why the crop 

 has been so little utilized in general farm practice. One reason is that 

 the plant has long been regarded as a pest, difficult to eradicate. This 

 view has now been dispelled, as a perusal of either Lloyd's or Westgate 



235 



