72 



THE FARMERS' REGISTER. 



The office of (he soil is, " 1. To receive and 

 digest the food designed lor the growing plant. 

 2. T'o serve as a niediun) lor conveying to the 

 spongiolels 'or rnoniiis oC ilie plants tlie water 

 holding in solution the diflerenl substances which 

 pass into and nourish them ; and, 3. To serve as 

 a basis for fixing the roots of the plants, and 

 maintaining them in an upright position."* 



The following are the most imporiani elemen- 

 tary principles, which, in various states of com- 

 bination enter into the composition of vegetable 

 matter, and (urnieh the appropriate food lor grow- 

 ing plan's ; oxygen, liydrogen, nitroiren and car- 

 bon, togeihcr vviili a email portion of ihe dikHlies 

 5ind oxides of various metals. Su lar as these 

 elementary principles are supplied from other 

 sources than the soil in whicli crops are grown, 

 the waste occasioned by their removal is replen- 

 itflied. Plants po?sess the power of decomposing 

 water,! and appropriating its elements by assimi- 

 lation as food; an(i as water is composed of hy- 

 drogen and oxygen, it Ibllovvs that two ofihe (ore- 

 going elements are derived in larL^e quantities 

 from the atmosphere through the mediunj o( rain, 

 snow and dews. 



Liebig, in various parts of his able work on or- 

 ganic chemistry, has shown that plants derive 

 from the atmosphere, by the absorbing power of 

 their leaves, a large and regular supply of carbon 

 in the form of carbonic acid. He adds that dur- 

 ing the heat of summer, (a plant) derives its car- 

 bon exclusively Irom the atmosphere. "| 



Here then we have the source whence is de- 

 rived in large quantities three of the principal ele- 

 ments, which in various stales ol' combination as- 

 sist in furnishing food lor growing crops. Nitro- 

 gen is known to be essential to the healthy and 

 vigorous growth of plants. This element exists 

 in large quantities in all animal substances, and 

 also to a considerable extent in decaying vegeta- 

 ble matters, but much of it escapes in the form of 

 ammonia during the process of decomposition. 

 It was difficult until recently to account for the 

 manner in which the loss (sustained by soils 

 while in cultivation) .of this indispensable ingre- 

 dient of fertility, is replenished. Liebig has shown 

 in a very satisfactory manner that ammonia (com- 

 posed of three parts, by weight, of hydrogen, 

 and 14 parts nitrogen) is combined with rain wa- 

 ter and snow in small quantities, and hence the 

 loss of nitrogen sustained by the removal of crops 

 from the soil on which they grew is, in a limited 

 degree, restored by the falling of rain and snow. 

 Thus nitrogen, to some extent, is also supplied by 

 the atmosphere to growing plants ; but as this 

 Bupply is not so abundant as that of the other ele- 

 ments, the utmost care should be used by the cul- 

 tivators of the soil to keep their lands well supplied 

 with this indispensable ingredient of fertility, by 

 taking nothing from the land but what is necessa- 

 ry, by restoring in the form ofmanure every thing 

 that can be restored, and by cultivating clover and 

 other ameliorating crops which take but little from 

 the soil, while they add to it all the fertilizing in- 

 gredients which they derive from the atmosphere. 

 When these circumstances are duly considered we 



* Farmers' Companion, p, 50. 

 t Liebifj's Organic Chemistry, 122. 

 X Liebia;",<: OrgJUiic Chemistry, p. 106. 

 51 and 55. 



Sec also p. 



may readily account for the length of time during 

 which a soil may be cultivated in the worst possi- 

 ble manner, without entirely exhausting it. A 

 continued effort is made by nature to replenish the 

 earth with those lertilizing ingredients which have 

 been inconsiderately wasted by the improvidence 

 of man, without any effectual effort on his part to 

 restore even the small ftroportion of those ingre- 

 dients which would furnish a full supply of food for 

 future crops. 



When a beneficent Providence has done so 

 much towards restoring the elementary principles 

 consiiluting the (bod of plants, which, to a certain 

 extent, must be consumed by the growing crops, 

 a stioiig encouragement is held out to the indus- 

 trious farmer to do his part also. In looking 

 around he beholds every where the evidence that 

 when all is restored to the earth which grew upon 

 it, a continued increase of fertility results. This 

 is a sure indication that a beneficent Providence 

 intended that Ihe earth should never become ste- 

 rile by cultivation — it plainly points out to man 

 that he too should restore to the soil that portion of 

 its products for which he has no use. He should 

 continually bear in mind that Ihe aids, provided by 

 a bountiful Creator, were only intended to supply 

 the unavoidable loss of nourishing ingredients or 

 food (or plants, occasioned by the necessity of 

 taking (iom the soil a portion of the growing crops 

 for consumption, and which cannot, therefore, be 

 fiilly restored. While, therefore, the prudent 

 farmer may confidently rely upon these aids in 

 preserving the (eriilit}' of his soil, he will recollect 

 that he must also do his part. He may take for 

 consumption the fruits of the earth for'both man 

 and beast, and yet give back to it enough to keep 

 up its original fertility, by restoring only a reason- 

 able proportion of that |)art ol its product which 

 remains after consuming all that is of any value 

 for food for himself and provender Ibr his stock. 



Next to oxygen, hydrogen, carbon and nitro- 

 gen, the alkalies, potash and soda, constitute the 

 most important ingredients, in the food of plants. 

 These were Ibrmerly considered as simple sub- 

 stances, but were ascertained, by Sir Humphry 

 Davj;^, to be metallic bases, combined with oxygen. 

 Tliey are therefore real oxides. They are capa- 

 ble of combining with a great variety of sub- 

 stances ; and, in various states of combination, 

 form an indispensable food for plants of almost 

 every kind. Hence if these substances were en- 

 tirely extracted from the earth, it could no longer 

 produce a vigorous growth of those plants which 

 require a supply of these alkalies as a part of their 

 food. 



Liebig has shown, that these alkalies exist in 

 a state of combination with water, in small pro- 

 portions, and that where they have been extract- 

 ed from the soil by growing plants, they may be 

 restored by irrigation, and by rain.* Sea water 

 also contains these alkalies in small quantities, 

 and Liebig informs us that " the roots of plants 

 are constantly engaged in collecting from the 

 rain those alkalies, which formed part of the sea- 

 water, and also those of the water of springs, which 

 penetrates the soil." That, " without alkalies 

 and alkaline bases most plants could not exist. "t 



The alkaline earths, lime and magnesia, are 



* Liebig's Organic Chemistry, 159, 160. 

 t Sec fill (her on (his subject, p^l96 to 200. 



