MONTHLY JOURNAL OF AGraCULTURE. 



ical point of view, tliat the physical proper- 

 ties of tlie soil become important, but also, 

 end indeed especially, as affecting the condi- 

 tion of drainage of l!ie ground. The greater 

 or less diyness of a soil influences powerfully 

 the nature of the vegetation it tends to nourish. 

 The {)la.Us of a marsh ditler from those of a 

 dry upland, not merely in greater or less 

 abundance or luxuriance, but in nature and 

 in organization. The plant which is naturally 

 funned lor dry ground will no more flourish 

 in a wet situation than an animal, inhabitant 

 of the land or air, can seek its subsistence, 

 and live habitually under water. It is, there- 

 fore, of vital importance to Agi'iculture, that 

 all supei-fluous water should be as rapidly as 

 possible removed. Its presence not merely 

 affects the character of the natural vegetation, 

 and renders the soil unfit for the cultivation 

 of plants which belong to a dry situation, but, 

 what is even more practical in its conse- 

 quences, it retards the pi'ogi'ess of vegetation 

 iu a very material degree, by preventing the 

 rays of the sun from warming the substance 

 of the soil A certain moderate heat is in- 



di8pensa]>le to vegetation ; an increase of heat, 

 provided it did not exceed cei"tain hounds, 

 augments its rapitlity and force in a remark- 

 able degree, and the constitution of ordiuaiy 

 soil, by its dark color and rugged, dull aspect, 

 is precisely such as to absorb the heat of the 

 sun with most effect, so as to advance the 

 vegetation on its surface ; but if the soil be 

 sensibly wet, no heating effect can take place, 

 all the warmth will be absorbed in producing 

 evaporation of water from the surface, and 

 rather, as one may verify by holding a wet 

 hand in the air, even before the sun, an im 

 pression of greater cold will bo produced. 

 Long experience as to the result has even 

 fixed, in orduiaiy language, the word cold as 

 expressing the imperfection of such soils. The 

 remedying of this evil, as of the former one 

 consists in relieving the soil from the excess 

 of water wliich lies upon it, which Ls to be 

 effected by attending to the general drainage 

 of the district, and by lessening the retentive 

 quality of the individual soil, where such is 

 economically practicable 



ROTATIONS. 



RELATION OF GRAIN CROPS AND GREEN CROPS — AMOUNT OF FOOD PRODUCED BY VARIOUS SI9- 

 TE.MS OF CULTURE — INFLUENCE OF DIFFERENT CULTURES IN THE EXHAUSTION OR AMELIO- 

 RATION OF THE SOIL. 



There is, however, another mode of re- 

 storing fertility which is of practical import- 

 ance, as it has led to the greatest of all im- 

 provements in husbandry, the rotation of 

 crops. A soil which has become exhausted 

 becomes restored by lying at rest for a cer- 

 tain time, particulaily if it be well broken up 

 and fresh surfaces be exposed to the action 

 of the atmosphere ; in fact, then, by the de- 

 composition of the mineral nia.sses which the 

 soil contains, a fresh soil is produced. The 

 orgaiiic remains of the former crops become 

 also rotted, and assume a form suited lor the 

 nutrition of young plants, and thus after a sea- 

 eon's fallowing, still more after lying out of 

 cultivation for some years, the soil resumes a 

 very considerable degree of fertility. But it 

 is evident that this pnjcess entails considera- 

 ble loss by the land being so long idle, and it 

 becomes of great importance to the farmer to 

 make some use of the land vs'hile this j)rocess 

 of regeneration is going on. This is actually 

 tlone by changing from one kind of culture 

 to another ; while the land is recovering from 

 the effects of one plant it is capable of .sus- 

 taining a plant which does not act upon it in 

 tae same way, and after this a thiid, differ- 



ently exhausting from either of the others, 

 will give a coume of rotation of three years, 

 during any two of which the gi'ound is recov- 

 ering from the^ exhausluig action of the plant 

 grown during the third. I take this oidy as 

 an example, for it is found that three years is 

 too short a term to be of much practical 

 utility. 



In selecting the plants adapted for such a 

 rotation, we must be guided by their chem- 

 ical composition, and by their mode of growth. 

 The results of both, however, lead to the 

 same conclusion. In addition to those ele- 

 ments which are common to all plants used 

 as food, certain plants are remaikable for the 

 great <piaiitity of silica they take from the 

 soil — such are the grasses and com plants ; 

 certain others for the pot;ish they take up — 

 such are turnips, the beet, the potato ; oth- 

 ers, again, for the quantity of lime — as the 

 pea, vetch, clover, tobacco, &c. Such are the 

 kinds of plants that should succeed each other 

 in a rotation, and the proportionate action of 

 each class may be judged from the following 

 fable derived from Liebig's investigations. 

 From a space of land of ^-47 acres, lie found 

 there were tidven up by 



Crop. 



Alkaline Salts. 



A crop of wheal lOiiJ lbs. 



A crop of peas I 1!I(J J 



A crop of beet wiiliout the leaves.. I :!G1 



Suits of Lime 

 and MnKiicsia 



78i lbs. 

 37J 



Silica. 



260 lbs. 

 •1(5 



The quantity of phosphates taken up by 

 these crops are — 



Pcau..n7lhs. Wheat.. H-J lbs. Beet. .:)r2 lbs 

 (7J«) 



The reason of the beet taking so little pno»- 

 phoric acid is, that it is not allowed to 

 form its seed, and iu all plants it is in the 



