FORAGE PLANTS 73 



moisture it receives whenever rain falls. It is not 

 unusual for single plants of alfalfa to have roots 

 fifteen to twenty-five feet long, burrowing down 

 to stores of moisture that no shallow-rooted plant 

 could get at. * 



Alfalfa is one of those nitrogen-gathering plants, 

 extracting the most precious of all the elements 

 of plant food from the air, and storing it in nodules 

 on the roots. When a plant dies its root decays, 

 and the soil is enriched by the nitrogen the nodules 

 set free. The fibre of the roots makes humus. 

 The roots have mellowed the deeper subsoil, and 

 brought up plant food to enrich the surface soil 

 for other plants. If the plant is left to rot, it, too, 

 adds fertilizer. But usually it is taken off in the 

 form of hay. The alfalfa plant gives back valuable 

 elements to the soil, and leaves it in better condi- 

 tion for the growing of such exacting crops as corn 

 and wheat. 



Another wonderful fact about alfalfa is that it is 

 perennial: once established, it continues to grow 

 in the same field, without "running out," for ten 

 to thirty years. And each year two to seven 

 cuttings of hay are made from the same field. 

 An average cutting yields between one and two 

 tons of dry hay. The average yearly yield is four 

 or five tons of dry alfalfa hay per acre. In' all 



