156 



bama it was found that vines gathered in October had from 1.45 to- 

 2.62 per cent, of nitrogen, while if left on the ground until January they 

 had only about 0.70 per cent., i. e., they lost two thirds of their most 

 valuable fertilizing ingredient. 



Experiments at the Louisiana station show that 1 acre of cow- 

 peas, yielding 3,970.38 pounds of organic matter, turned under, gave 

 to the soil 64.95 pounds of nitrogen, 20.39 pounds of phosphoric acid, 

 and 110.56 pounds of potash, of which at least 8.34 pounds of nitro- 

 gen, 4.43 pounds of phosphoric acid, and 18.1 ponnds of potash were 

 furnished by the roots. Analyses made at the South Carolina Station 

 show that cowpea hay contains 1.42 per cent, of potash, 0.39 per cent, 

 of phosphoric acid, and 2.71 per cent, of nitrogen. Cowpea roo's con- 

 tained 1.19 per cent, of potash, . 28 per cent, of phosphoric acid, and 0.94 

 per cent, of nil rogen ; the roots and stubble, two months after the 

 crop was harvested, contained 0.83 per cent of potash, 0.26 per cent, 

 of phosphoric acid, and 1.35 per cent, of nitrogen. Experiment else- 

 where showed that the vines from a given area weighed six times as 

 much as the roots, and were b$ times as valuable for manure. 



Cowpeas and melilotus have given good results as green manure on 

 the canebrake lands of Alabama. " Before the land was sowed in meli- 

 lotus and cowpeas it was not considered worth cul'ivating. This 

 season (1890) it produced as fine a crop as the best lends of the s'ation. 

 highly fertilised." 



Alfalfa 



Alfalfa or lucern has leng been cultiva'ed in Europe, and is grown 

 quite extensively in some of the "Western and Southern States. It 

 seems probable that it may be introduced with advantage into many 

 parts of the Southern States east of the Mississippi, and over a wide tract 

 of the more arid regions of the Southwest. Under favourable conditions 

 it will live from eight to fifteen years, and does not run out as clover 

 does. It has been grown successfully for seven years at the experiment 

 station at Geneva, N.'Y., but in recent experiments on 30 farms in 

 different parts of Vermont it was very largely winterkilled. "While a 

 Southern climate is more favourable to alfalfa, numerous experiments 

 have shown that it will do well in many localities in the Northern 

 State*, and when established will produce from three to five crops each 

 season for a number of successive years. Alfalfa is said to be especially 

 adapted to dry climate*, and withstanels drought much better than 

 ordinary clovers. For this reason it is largely relied on in Colorado 

 and California, especially where irrigation is used. 



The value of alfalfa for green manuring has been quite thoroughly 

 studieel by the New Jersey Experiment Station. Seed was sown broad- 

 cast at the rate of 15 pounds per acre. A fertiliser containing phos- 

 phoric acid and potash with a little nitrogen was applied. It appears 

 from these studies that alfalfa derives nitrogen from some other source 

 than the soil, anel draws potash through its long roots from the deeper 

 layers of the subs* il. In three years 90 pounds of nitrogen per acre 

 was applied in the fertiliser, and the creps harve steel in that time con- 

 tained 91 2 . 8 pounds of nitrogen per acre. The fertilising materials 

 containeel in the crops harvested in four years are shown in the follow- 

 ing table : 



