54 



THE MONTHLY BULLETIN. 



US concentrated fruit or vegetable products as to make beef or mutton. 

 A ton of alfalfa takes from the soil 44 pounds of nitrogen, 8.27 pounds 

 of phosphoric acid, 50.95 pounds of potash and 40 pounds of lime. As 

 we have seen, alfalfa is strong in quantity of material, and so will give 

 a maximum amount of humus, and is very rich in nitrogen, the most 

 costly fertilizing element. Thus it is without a rival as a manurial farm 

 crop. We have already praised it as one of the best foods for farm 

 animals, and thus if we feed it to our stock we get a double profit — first, 

 in the meat or milk products which it produces, as does no other agri- 

 cultural crop, and secondly, it furnishes a large amount of farm yard 

 manure of verv high value. 



Fig. 8. — Stem of alfalfa showing arrange- 

 ment of leaves and flowers. («) spiral seed 

 pod, lateral view; (b) same, showing tip of 

 pod; (c) seeds. (From A. L Root Co.) 



ENRICHES THE SOIL. 

 As we shall see, alfalfa is, like clover, beans, peas, etc., a legume and so 

 attracts countless bacteria to make home and food of the tubercles 

 which they cause, and which we can see by observing its roots. As we 

 know, the"^asmosphere is four fifths nitrogen, but this the higher plants 

 can not use in the uncombined state. But, as we have seen, micro- 

 organisms, infinitesimally small, may exist already in the soil, collect 

 upon the roots of legumes, appropriate the nitrogen of the air as we 

 do the oxygen, combine it with some mineral base and so form nitrates 

 which the" higher plants can now utilize, and thus the plants are supplied 

 with the necessary and most expensive fertilizing element, nitrogen. 

 As already noted, 'the deep rooting finds added stores of potash and the 



