r.RAIN AND ITS CULTIVATION. 109 



improved when it contains either naturally or artificially a 

 large proportion of lime. Many light and all marly or cal- 

 raivoiiti soils;, if in proper condition, will give a good yield 

 of wheat. Lime is an important aid to the full and certain 

 growth of wheat, checking its exuberance of straw and its 

 liability to rust, and steadily aiding to fill out the grain. A 

 rich mellow turf or clover ley is a good bed for it ; or land 

 which has; been well manured and cleanly cultivated with 

 roots or corn the preceding year. Fresh barn-yard manure 

 applied directly to the wheat crop, is objectionable, not only 

 from its containing many foreign seeds, but from its tendency 

 to excite a rapid growth of weak straw, thus causing the 

 grain both to lodge and rust. The same objection lies 

 against sowing it on rich alluvial or vegetable soils ; and in 

 each, the addition of lime or ashes, or both, will correct, these 

 evils. A dressing of charcoal has in many instances, been 

 found an adequate preventive ; and so beneficial has it 

 proved in France, that it has been extensively introduced 

 there for the wheat crop. A successful example of uninter- 

 rupted cropping with wheat through several years, has been 

 furnished by a Maryland farmer, who used fresh barn-yard 

 manure with lime. But this is an exception not a rule, and 

 it will be found that profitable cultivation requires, that wheat 

 should take its place in a judicious rotation. The great pro- 

 portion of silica in the straw of cereal grains, (amounting in 

 wheat, barley, oats and rye, to about four-fifths of the total 

 of ash from the grain and straw,) shows the necessity of 

 having ample provision made for it in the soil, in a form 

 susceptible of ready assimilation by the plant. This is af- 

 forded both by ashes and from the action of lime upon the 

 soil. 



Depth of soil is also indispensable to large crops. The 

 wheat plant has two sets of roots, the first springing from 

 the seed and penetrating downwards, while the second push 

 themselves laterally near the surface of the ground from the 

 first joint. They are thus enabled to extract their food from 

 every part of the soil, and the product will be found to be in 

 the ratio of its extent and fertility. Under-draining and 

 sub-soil plowing contribute greatly to the increase of crops, 

 and it is essential that any surface water be entirely removed. 

 Wheat on heavy clay lands are peculiarly liable to winter 

 kill unless they are well drained. This is owing to succes- 

 sive freezing and thawing, by which the roots are broken 

 or thrown out. When this is done to a degree that will 



