98 GRASSES AND FORAGE PLANTS.* 



that of clover for the first year, requiring a soil thoroughly 

 mellowed and prepared by clean and careful tillage ; and the 

 want of proper attention to this point has led to partial fail- 

 ures in the attempts to raise it in this country. It suffers and 

 languishes in compact clay soils, and does not flourish in light 

 soils lying over an impermea1:>le subsoil, wliich prevents the water 

 from running off. It will never succeed well on thin soils. 

 But in a permeable subsoil, consisting of loam, or sand or 

 gravel, its roots can penetrate to great depths, and being nearly 

 destitute of lateral shoots, provided with numerous fibrous 

 rootlets, or radical ofif-shoots, imbibe their moisture and nutri- 

 ment in layers of soil far below the average of other plants. In 

 this respect it differs materially from clover. For lucerne, a 

 suitable subsoil is of the utmost consequence. For the short 

 lived red clover, a suitable surface soil is more important ; a 

 want of care and deep tillage, especially a neglect to break 

 through and loosen up the hard-pan wherever it exists, will 

 inevitably lead to failure with lucerne. But when the soil is 

 suitable, it will produce good and very profitable crops for from 

 five to ten or twelve years, and, of course, it does not belong in 

 the system of short rotations. 



But notwithstanding the large quantity of succulent and 

 nutritious forage it produces, its effect is to ameliorate and 

 improve the soil rather than to exhaust it. This apparent 

 anomaly is explained by the fact that all legiiminous, broad 

 leaved plants derive a large proportion of their nutritive mate- 

 rials from the atmosphere, and that a vast quantity of roots are 

 left to decay in the soil when it is at last broken up, varying, of 

 course, with the length of time the plant continues in the soil, 

 while the luxuriant foliage serves to shade the soil and thus to 

 increase its fertility. Much of this rich foliage is scattered and 

 left to decay, as is the case with all similar plants at the time of 

 harvesting, and the growth of the aftermath is also usually very 

 considerable. The fact that it actually increases the fertility of 

 the soil for other plants, has often been proved and may be 

 regarded as fully established. A soil which would bear only a 

 medium crop of wheat at first, produced a greatly increased 

 quantity after being laid down to lucerne a few years till its 

 roots had enriched the soil. 



Lucerne should not follow immediately after having been. 



