133 



fertilizing effect of cowpeas that it was not entirely 

 obscured even when nitrate of soda was also employed, 

 the increase in the yield of oats under these conditions 

 being 29 per cent. 



Coicpeas as fertilizer on lime land. — A co-operative 

 fertilizer experiment was conducted for this Station 

 by Capt. A. A. McGregor on lime land at Town Creek, 

 in North Alabama. In his experiment the coT\T)ea was 

 the legume employed. 



In 1898 cowpeas were grown on certain plots and cot- 

 ton on others. The cowpea vines, on which no fruit had 

 matured, were plowed under in the spring of 1899. 

 Cotton was planted on plots which had borne a crop of 

 cotton in 1898 and on others which had grown cowpeas 

 for fertilizing purposes. All cotton plots referred to 

 in this paragraph were unfertilized in 1899, and the 

 fertilization of cowpeas and cotton in 1898 had been 

 identical, only phosphate having been used with either 



crop. 



The weather was exceedingly unfavorable in 1899, so 

 that the full measure of the fertilizing value of cowpeas 

 was not revealed in this test. 



In this case the average increase in the yield of seed 

 cotton, which we mav attribute to the cowpea vines is, 

 even under very adverse conditions, 58 per cent., or 125 

 pounds, worth at 2^ cents per pound, $3.92 per acre. 

 Doubtless later crops have also been benefited by the 

 fertilization with cowpeas. 



There is reason to expect a larger increase than the 

 above when cowpeas are plowed under on the lime lands 

 of either the Tennessee Valley or of the Central Prairie 

 Region of Alabama. Especially in the prairie soils the 

 principal need is for vegetable matter to lighten the soil 

 and to add nitrogen, and for these purposes the choice 

 must usually be made between melilotus (the so-called 

 lucern) and co^i)eas. 



