86 STATE POMOLOGICAIv SOCIETY. 



can be saved only by secondary crops, which grow until stopped 

 by the severe weather of winter. Even in cases where the 

 leaching of soils is not excessive a deep-rooting cover crop brings 

 up plant food from the subsoil and leaves it near the surface ta 

 be used later by the trees. 



Besides preventing in part the loss of fertilizing elements 

 from the soil, cover crops may serve as a direct fertilizer. For 

 this purpose the well-known ability of leguminous plants to take 

 nitrogen from the air and store it^ so that it can be used later 

 by other plants, is made use of. The use of such crops in ordi- 

 nary farm rotations is well known. That they may be equally 

 useful in case of orchard fruits is shown by tests at the New 

 Jersey Station. Crimson clover was sown in the peach orchard 

 on sandy soil in the latter part of July, and the crop was 

 plowed under in the latter part of the following May. The 

 cover crop retarded to growth of the trees somewhat in the 

 spring, but after it was plowed under they gained rapidly, and 

 both wood growth and fruitage were more satisfactory than in 

 the remainder of the orchard, which was fertilized with nitrate 

 of soda. The use of leguminous crops, however, is not to be 

 recommended in all cases. It often happens that soils become too 

 rich in nitrogenous fertilizers, and the trees, therefore, grow 

 too vigorously, do not mature their wood well, and are unfruit- 

 ful. In such cases leguminous crops should not be used. 



Cover crops may also improve the physical condition of the 

 soil. In this connection the relation of humus to the water- 

 holding capacity of the soil has been already noted. Humus 

 is also beneficial in changing the character of very heavy soils, 

 making them more porous and lessening their tendency to 

 puddle in wet weather. Cover crops which live through the 

 winter are of use in drying out heavy wet soils in spring so as to 

 allow cultivation. 



Cover crops may also be advantageous in protecting the 

 trees and fruit. The Delaware Station reports lessened injury 

 to fruit blown from the tree where the soil was covered with 

 a crop of crimson clover. In the extreme North, cover crops 

 are thought to be of advantage in preventing deep freezing 

 and alternate freezing and thawing of the soil and the conse- 

 quent injury to the roots of trees. At the Delaware Station 



