1572 



The Cornell Reading-Courses 



the water table should be not nearer than two feet from the surface for 

 more than a few days at a time, and is better at about four feet below the 

 surface. 



The root system of alfalfa varies with soil conditions. In a porous soil, 

 easy to penetrate, the taproot will extend almost straight downward for 



lo to 20 feet, or until the 

 water table is reached. How- 

 ever, if a stratum of hard soil 

 is encountered, the taproot 

 (\^,1 X-.i' ^^'(\ will break up into a much- 

 ^^ \\\\\'\'^\ branched root system. In a 

 nvi\\\ inn^ very compact soil the roots 

 m.ay not penetrate more than 

 3 or 4 feet, even when the 

 plants are several years old. 



■'/'J * VA 



K 



/A 



;^' 



Fig. 236. — Drawing 

 showing distribution 

 of roots on a deep 

 porous soil, and on 

 a compact soil. In 

 the first case a long 

 taproot is developed, 

 while in the second 

 case the taproot 

 breaks up into many 

 branches 



LIME REQUIREMENTS 



Field and forage crops vary in their requirements 

 of lime, or basic substances in the soil. Redtop and 

 alsike clover will tolerate some acid in the soil, while 

 many of our most important field crops, such as 

 oats and buckwheat, seem to be quite indifferent to 

 the presence of lime so long as the soil is not acid. 

 Certain crops, notedly red clover and alfalfa, are very 

 sensitive to the lack of lime. In order to grow alfalfa, 

 lune must he applied to at least three fourths of the culti- 

 vated soils of New York. 



By areas in New York State 



The map herewith (Fig. 237) shows the State 

 divided into four principal soil areas, according to 

 lime requirements for alfalfa. Where the soil has been derived in general 

 from a lim.estone formation, as in Section I, it usually will not be 

 necessary, to add more lime. The presence of limestone pebbles or 

 stones ordinarily indicates sufficient lime, while the absence of lime- 

 stone pebbles usually, but not always, indicates the need of lime. 



When lime is required, in Section I generally 500 to 1,000 pounds of 

 quicklime will be sufficient, or twice this amount of ground limestone. In 

 Section II, 1,000 to 2,000 pounds of quicklime, or twice this amount of 

 ground limestone, will usually be sufficient. In Section III the soil is 

 generally very deficient in lime, and 2,000 to 4,000 pounds of quicklime, 

 one half as much more of hydratcd lime, or twice as much ground lime- 



