18 BEPOKT OX THE Yo. 33 



That a cover crop may be of the greatest value, it should be capable of withstand- 

 ing the winter and continuing its growth next spring. This, however, is not a neces- 

 sity, as many of the ordinary crops which will not live through the winter are valuable 

 for this purpose. 



Different soils require different kinds of crops. This has led to a division of cover 

 crops under several classes. The most important are the nitrogen gatherers, which 

 through the agency of the nodules on the roots can make use of the nitrogen of the 

 air. Such plants as clover, vetches, alfalfa, peas, and beans, belong to this class, and 

 should be used where the soil is deficient in nitrogen. Another class is known as the 

 potash liberators, such as turnips and rape, which, although they do not add anything 

 to the soil, as do the leguminous plants, yet change the form of the mineral potash so 

 that it may be more readily acted upon by the roots of succeeding crops. Then there 

 is a third class, commonly grown, such as rye, oats, and buckwheat, which are valuable 

 chiefly on account of the humus formed by their development. 



Hairy Vetch, sown at the rate of thirty-five pounds per acre, forms a very close 

 mat over the ground. This is a valuable crop owing to the fact that it collects nitrogen, 

 lies close to the ground so that it does not inconvenience the pickers when gathering 

 the fruit, and also withstands the cold winter and continues its growth early in the 

 spring. 



Red Clover and Mammoth Clover, sown at the rate of twenty-five to thirty pounds 

 per acre, are about equal in value, make a fair growth, are low growing, and winter 

 well on drained soil. 



Crimson Clover has not made quite as good growth as the red or the mammoth, 

 nor will it stand the winter in the colder sections, which is a serious disadvantage. 

 Best sown thirty to thirty-five pounds per acre. 



Alfalfa, or lucerne, is one of the best leguminous crops for dry land. It makes a 

 good growth and winiors well. There is a mistaken impression that alfalfa will not 

 make sufficient top the first season. Thirty pounds of seed per acre, sown in July, 

 will give a good stand the same season. 



Rape has given good results in the colder sections. It makes a heavy growth of 

 stiff stems, which, although nearly all killed in winter, stand up well enough to hold 

 the snows. Rape can scarcely be recommended for fruiting apple orchards, as it re- 

 mains wet the greater part of the day, making the work of harvesting very unpleasant. 

 It may be used to good advantage in the rotation, especially if few fruits are to be 

 harvested. 



Rye, the favorite crop of many growers, gives a fair amount of top and winters 

 well. One advantage of rye is that it may often be grown on lands not in a physical 

 condition for the growth of clover. In this way humus may be added to the soil, and 

 conditions made more favorable for the grow r th of clover. 



MAINTAINING FERTILITY. 



The maintenance of fertility is more frequently neglected in the orchard than 

 on any other part of the farm. Trees, even on poor land, will produce fruit, but it is 

 only on soils where fertility is maintained that paying crops are produced. Each year 

 that fruit is harvested some plant food is removed. If profitable crops are to be ex- 

 pected the supply of plant food in the soil must be maintained. 



The most essential elements for the production of fruit are nitrogen, potash, phos- 

 phoric acid, and lime. Nitrogen encourages leaf and wood growth, which are essential 

 to the development of the tree and to the production of the best quality of fruit. Potash 

 is an essential constituent in the growth of fruits. It constitutes a large proportion 

 of the ash of the wood and more than 50 per cent, of the ash of the fruit, and is also 

 associated with the development of flavor in the fruit. Phosphoric acid is essential 

 to the development of the tree and the proper ripening of the fruit. Lime is not in 

 itself an essential element, but is necessary in liberating plant food. 



