264 Illinois State Dairymen's Association, 



yielded an average increase of a little more than 40 per cent 

 induced by the cowpea. In one case a plot sown to cowpeas in 

 the spring produced $18 worth of hay and was followed by a 

 crop of oats valued at $18.50, making the returns from the acre 

 $36.50. Another plot of oats that had not followed cowpeas 

 yielded only $11.58 worth of oats. In the same length of time 

 the plot planted to cowpeas and oats yielded $36.50, while the 

 oats alone yielded only $11.58. This was an increase in value 

 of more than 300 per cent, and the soil was more fertile at the 

 end of the period than it was at the beginning. In another cease 

 cowpeas grown just before a crop of wheat and cut for hay, pro- 

 duced $19.33 worth of hay and the pea stubble increased the 

 yield of the following crop of wheat 61 per cent. The wheat 

 was valued at $13.20, making a total of $32.53 against $8.08 

 worth of wheat grown on an adjacent plot and not preceded by 

 a crop of cowpeas. This represents a 400 per cent increase in the 

 value of the products taken from the soil, due solely to the grow- 

 ing of one crop of cowpeas before the soil was seeded to wheat. 

 In this case the value of the cowpea hay was $6.13 more than the 

 val\ie of the crop of wheat, notwithstanding an increase of 61 

 per cent in the yield of wheat from the fertilizing effects of the 

 cowpea stubble. These tests were made on a light sandy soil, 

 deficient in vegetable matter, and would ordinarily produce ten 

 or twelve bushels of wheat. This character of soil prevails 

 throughout the South. It responds promptly and profitably to 

 fertilization, and particularly is the response noticeable where 

 the fertilization is brought about by the application of bulky 

 vegetable materials of approved composition, such as leguminous 

 plants, stable manure and the like. Such materials not only give 

 better returns than are secured from the use of commercial fertil- 

 izers, but the effects are more lasting. They increase the moist- 

 ure-holding and moisture-retaining properties of the soil, 

 improve its physical properties and present conditions more fav- 

 orable to nitrification. 



In 1889, a series of tests were inaugurated for the purpose 

 of determining the residual effects of the manural constituents 

 of cowpeas as compared with commercial fertilizer. These tests 

 were made with wheat, and the phosphoric acid, potash and 

 nitrogen of the fertilizers were combined in the proportions 



