Thirty-fourth Annual Convention. 2^' 



than the yield of plots 1 and 12, receiving no manures, whili 

 the first year's yields shows an increase of 6.5 bushels from the 

 nitrate of soda plots over plots 1 and 12. Comparing the plots 

 fertilized with nitrate of soda with plots 4 and 11, we have an 

 average yield of 2.15 bushels more from the stubble plots than 

 from the nitrate of soda plots for the first year, while the value 

 of the cowpea hay removed from the stubble plots was worth 

 approximately three times as much as the nitrate of soda cost. 

 The gross average yield of the stubble plot produced in the four 

 years 7 bushels of wheat more than the nitrate of soda plots. 

 This shows four items of profit derived from the stubble plots 

 as compared with the nitrate of soda plots : 



First, the saving of the cost of nitrate ; second, an increased 

 yield of 7 bushels of wheat ; third, the value of hay cut from the 

 stubble, and fourth, the 16 per cent increase in fertility of the 

 land. After cutting the cowpea hay between the crops of wheat 

 (plots 2 and 13) there remained in the soil an increase in fertil- 

 ity sufficient to produce in four years 17.55 bushels more wheat 

 than was grown on plots 1 and 12, where wheat followed wheat 

 for four years without cowpeas between, thus giving an increase 

 of 40.8 per cent in the yield of wheat and in addition cowpea hay 

 equal in value to the wheat grown on the same plots. 



When the character of the soil upon which these experi- 

 ments were conducted is taken into consideration, it is more 

 than probable that the residual effect of whatever manural sub- 

 stances applied would be more lasting in soils less open and more 

 retentive. This soil is a deep, gravelly, sandy loam, rolling, and 

 has a somewhat porous subsoil. On the other hand it is just 

 such soils that are more permanently benefited by the applications 

 of slowly decomposing organic matter than by less lasting fertil- 

 izing materials. The 800 pounds of fertilizer on plot 9 plowed 

 in at the same time as the cowpea vines of plot 10 gave .3 of a 

 bushel more wheat in 1899, but 2.6 bushels less in 1902, under 

 identical treatment from October, 1898, to June, 1902, while 

 the fertilizing effects of the one crop of cowpeas plowed in in 

 the fall was greater than the fertilizing effects of 800 pounds of 

 complete fertilizer applied at the same time, adding 7 bushels of 

 wheat to the yield in four years and leaving the soil more fertile 

 at the end of four years than the 800 pounds of fertilizer left it. 



Just how long the continuous growing of wheat (or other 



