CROPS 



149 



As already stated, the leguminous plants are remarkable 

 for the large amounts of nitrogenous matter, potash and lime 

 which they contain. Their power of collecting nitrogen from 

 the air by the aid of the micro-organisms in the nodules on 

 their roots renders their after-eflfect on land of great value (see 

 p. 105). 



Lucerne {Medicago sativa)^ known as alfalfa in America, is 

 particularly valuable in hot, somewhat dry climates, since 

 when once established its deep-reaching roots enable it to 

 bring up water from the subsoil and to stand long drought. 

 It will then yield repeated cuttings of valuable forage for many 

 years. Other valuable leguminous fodder crops are red clover 

 {THfolium pratense), crimson clover (T. incarnatum), white 

 clover {T. repens), alsike clover (T. hyhridum), sainfoin [Ono- 

 hrychis sativa), trefoil [Medicago lupulina), vetches or tares 

 (Vicia saliva) and serradella {Ornithopus sativus) . The charac- 

 teristic of the leguminous crops is their ability to grow on 

 soils poor in nitrogen, provided mineral constituents are 

 sufficiently abundant. 



Composition of Green Lequmingus Fodder. 



8. Miscellaneous Fodder Crops. — PHckly Comfrey 



{Symphytum asperrimum). — This plant has been from time 

 to time highly praised as a forage crop, but has not received 

 much public favour. It is a shrubby, perennial plant, 



