PERENNIAL FORAGE GRASSES 3! 



to economic conditions as the difficulty of plowing the land, 

 and the relative adaptability or value of different crops. Be- 

 ginning with land which would hardly produce 500 pounds of 

 hay to the acre, the Rhode Island Station by means of a six- 

 course rotation consisting of rye one year; grass (timothy 15, 

 redtop 7.5, red clover 7.5 pounds) three years; maize one year; 

 and potatoes one year; and by means of rather heavy applica- 

 tions of commercial fertilizers each year, and the use of lime 

 has secured hay crops averaging 4 tons or more per acre. 



Land used for pasture is often the least arable portion of 

 the farm and, in such case, not likely to enter into the general 

 system of rotation. When it does enter into the rotation, dif- 

 ferent grasses are required than when the pasture is permanent. 

 It is not advisable to sow Kentucky blue grass, meadow fescue, 

 or meadow foxtail unless the land is to remain in pasture for 

 more than three years. Where, from lack of adaptation of 

 suitable grasses for pasture, it is necessary to use grasses and 

 clovers of short duration, then pastures, like meadows, must 

 be renewed by plowing and re-seeding. 



With suitable grasses, pastures may be permanent. In Eng- 

 land pastures are believed to improve with age, pastures having 

 existed there for such long periods that there is no record of 

 the land having been plowed, although the existence of fur- 

 rows is evidence that they have been. While pastures may be 

 permanent, a rotation of crops may occur. Not only may 

 different species occupy the same spot at different times, but 

 the proportion of different species will vary with climatic and 

 soil conditions. 



30. Fertilizing Elements. Experiments by Lawes and Gilbert 

 conducted on a large scale and extending over many years 

 show that nitrogenous manures act most beneficially on grasses, 

 while potash manures are most beneficial to leguminous plants. 

 While the results of American stations tend to confirm the 

 principles involved in the English experiments, the results in 



