578 IOWA DEPARTMENT OF AGRICULTURE 



Many soils that at present are not fit for alfalfa culture may be made so 

 by providing drainage facilities, correcting acidity, adding organic matter, 

 or supplying needed plant food, according to the requirements. Good 

 drainage is essential in order that the roots may go deep into the soil. 

 Hardpan must be broken up or avoided altogether. Soils that are sour may 

 be made sweet by thorough drai'nage and the application of lime. A good 

 supply of decomposable organic matter in the soil helps the bacterial 

 action in making plant food available, facilitates the inoculating process, 

 and together with good drainage prevents heaving in the spring. 



Muck soils may be used for alfalfa if they are well drained and prop- 

 erly supplied with mineral plant food. Potash is nearly always lacking 

 in these soils and often phosphoric acid and lihie must also be supplied. 

 Soils that are subject to flooding are not good for alfalfa. 



SOIL FERTILIZATION. 



Alfalfa requires large quantities of plant food and cannot be expected 

 to do well on poor soils. Its deep rooting habits may enable it to extract 

 more food from the soil than most other crops, but to secure large yields 

 there must be an abundance of food within easy reach and if the soil is 

 not naturally well supplied, manure or commercial fertilizer must be 

 added. After it is thoroughly established and properly inoculated with its 

 nitrogen gathering bacteria, alfalfa will supply itself with nitrogen from 

 the air, but all potash, phosphoric acid, and other mineral food must come 

 from the soil and as the crop is naturally a large producer, large quantities 

 are required. Of the plant food that must come from the soil, potash and 

 phosphoric acid are most largely required and these are the two substances 

 in which the soi'l is most likely to be deficient. Every ton of alfalfa hay 

 which is removed from the land takes with it about 11 pounds of phos- 

 phoric acid and 49 pounds of potash. 



Every alfalfa field should be started with a liberal dressing of stable 

 manure, if possible. Experiments have proven time and again that manure 

 is unusually valuable in starting alfalfa. It not only supplies plant food 

 but improves the physical condition of the soil and facilitates the inocu- 

 lating process. In many of the experiments conducted by this station, 

 special inoculation of the soil was found unnecessary when plenty of 

 manure was applied. 



When sufficient manure is not available and the soil is not already 

 rich, a high grade commercial fertilizer should be used. Just what will 

 be required will depend upon the character and condition of the soil. 

 In most instances, however, it will be well to use a fertilizer rich in both 

 phosphoric acid and potash. A mixture containing a little nitrogen, per- 

 haps 2 per cent, and 8 to 10 per cent of phosphoric acid and the same of 

 potash, applied at the rate of three or four hundred pounds per acre will 

 be sufficient unless the soil is quite poor, in which case heavier applications 

 may be profitable. The fertilizer should be disked into the ground some 

 time in advance of seeding. 



LIMING SOLLS FOB ALFALFA. 



To what extent Indiana soils are in need of liming in order to success- 

 fully produce alfalfa is not definitely known. It is known, however, that 



