ALL ABOUT ALFALFA. 343 



constituents of plants, such as phosphoric acid, potash, 

 lime, etc. , are derived solely and entirely from the soil. 

 In the case of nitrogen, certain leguminous plants, 

 such as alfalfa, clover, and peas, have the power of 

 assimilating large amounts from the atmosphere when 

 sufficient phosphoric acid, potash, and lime are pres- 

 ent in the soil. Therefore, while it is quite possible 

 that alfalfa, being a deep-rooting plant, could secure 

 nitrogen from the soil, the probability that it also 

 secures a large quantity from the air enhances its 

 value as an agricultural plant — firstly, because nitro- 

 gen is the basis of the compound protein, the most 

 valuable part of the food produdl ; and, secondly, be- 

 cause nitrogen is the most costly element in all ferti- 

 lizing compounds. When alfalfa is grown and its 

 produdls are properly utilized upon the farm, it cannot 

 be considered an exhaustive crop, but rather as one 

 fulfilling the proper aim of rational agriculture, which 

 is to transform into produce the raw materials at our 

 disposal in the atmosphere and soil. It has been 

 estimated that the market value of an acre of turned- 

 under green alfalfa is all the way from fifty dollars to 

 eighty dollars, and the experiments along this line 

 have been very carefully made by scientific gentlemen. 

 Alfalfa in Rotation. — With proper rotation with 

 alfalfa as a base, land can be farmed indefinitely with 

 no outlay for fertilizers and without summer fallowing. 

 The obje(5l sought in rotation is to produce the great- 

 est possible value and at the same time keep the land 

 in good condition. A farm is assumed to be divided 

 into four equal plats and the following shows the crops 

 to be raised for four years from the sod. A supply of 



