SOILS. 23 



tion. If it is of a clayey nature, that prevents the escape of water, and thus permits an 

 accumulation on the surface, many crops will be seriously injured by heavy rains. Soils 

 having such a subsoil will be greatly benefited by under-draining, and this should be done 

 if possible. Some recommend breaking up and loosening this hard strata with a subsoil 

 plow. This should be cautiously done, however, for unless the subsoil is of a nature to ben 

 efit the surface soil by mixing with it (which is rarely the case), or additional manure be 

 applied, the latter will be injured by the mixing ; for, while deep plowing is very desirable in 

 some soils, furnishing additional moisture to the roots of crops, and admitting the air, besides 

 increasing the depth of the soil, and obviating the effect of drouth in the hot season, still, with 

 other soils, it is a positive injury, and the few benefits derived are more than counterbalanced 

 by the evil effects upon the soil of bringing up coarse gravel or other undesirable materials 

 to the surface. If the subsoil can be broken or loosened without mixing with the surface 

 soil, much benefit may be thus derived. Since soils differ so greatly in character, only gen 

 eral rules can be given in this respect- the farmer being able to judge of the nature of his 

 own soil, must be guided accordingly. 



When the subsoil is porous and leachy, readily permitting the escape of not only water, 

 but the soluble portions of manure and other fertilizing elements, the above-mentioned pro 

 cess of subsoil plowing would be very injurious, since the sand or gravel would be brought 

 to the surface and mixed with the fertile surface soil. Most writers recommend in such 

 cases the deepening of the surface soil by the addition of vegetable manures, in order to 

 afford greater depth for the roots and thus increase the moisture. This is a laborious and 

 expensive process, however, and such lands make usually the best return for what is expended 

 by being kept as permanent wood or pasture lands. 



If the subsoil and surface soil be of such a nature as to be improved by mixing, such 

 as the one being of a sandy or gravelly nature, the other of a clayey or marly character, the 

 mixing of the two soils by deep plowing will be very advantageous, since the very ingredi 

 ents wanting to perfect or improve the surface soil will thus be furnished. 



Allen, in his American Farm Book, says: &quot;The effect of long-continued cultivation, 

 besides exhausting what is essential to the earthy part of plants, is to break down the coarser 

 particles of the soil, by the mechanical action of the plow, harrow, etc., and in a much more 

 rapid degree, by the chemical combinations which cultivation and manuring produce. A 

 few years suffice to exhibit striking examples in the formation and decomposition of rocks 

 and stones. Stalactites and various specimens of limestone, indurated clays, sandstone, and 

 breccias, or pudding stones, are formed in favorable circumstances, almost under our eye; 

 while some limestones, shales, sandstones, etc., break down in large masses annually, from 

 the combined effect of moisture, heat and frost. The same changes, on a smaller scale, are 

 constantly going forward in the soil, and much more rapidly while under cultivation. The 

 general tendency of these surface changes is towards pulverization. The particles forming 

 the soil, from the impalpable mite of dust to the large pebbles, and even stones and rocks, 

 are continually broken up by the combined action of the vital roots and the constituents of 

 soils, by which new elements of vegetable food are developed and become available, and in a 

 form so minute as to be imbibed by the spongioles of the roots, and, by the absorbent vessels, 

 they are afterwards distributed in their appropriate places in the plant. Where this action 

 has been going on for a long period, a manifestly beneficial effect has immediately followed 

 from bringing up and mixing with the superficial earth portions of the subsoil which have 

 never before been subject to cultivation. 



&quot; A subsoil which is permeable to water is sometimes imperceptibly beneficial to vegeta 

 tion, not only by allowing the latent moisture to ascend and yield a necessary supply to the 

 plants, but a moisture frequently charged with lime and various saline matters, which the 

 capillary attraction brings from remote depths below the surface. It is probably from this 



