ARABLE LAND. 



ARABLE LAND. 



A loam .t Chamart, highly prUed by gardeners about Parta, M the 

 basis of their utiAcM M&, ooobu of 



ArgOkuMou* Mod 



Finely divided oUy 



Siliceous sand 



Carbonate of lime, coarse 



Ditto, fine 



Woody fibre 



Humus and soluble matter 



Pirt. 

 57 

 S3 



1 



0-5 

 0-5 



100 



The argillaceous MUM] ii compoeed of fragments of soft (tone, which 

 >.^. moisture, and do not bind hard ; the small proportion of humus 

 of no oonsoquaiim where manure ia to be had in any quantity. 

 A TOT rich heath or bog-earth found at Meudon, owl in great 

 [inert for flowers and in composts, consists of 



a of no 



: 



Oritty ailic 



:..;. ' 

 I ! 



Vegetable fibres partly decomposed 

 Humus ...... 



Carbonate of lime .... 



Soluble matter 1 - 



Part., j 

 62 

 20 

 16 

 0-8 



100 



This soil, like our bog earth, would be very unfit for the growth of 

 corn, but, from the quantity of vegetable matter, ia highly um-ful in 

 composts and artificial soils. Mixed with lime, it would make an 

 excellent top-dressing for moist clay soils. 



The above analyses give but a rough idea of the composition of a 

 oil ; in bet they for the nifwt part indicate those causes of fertility or 

 barrenness in soils, which reside in their varying texture or in their 

 relation* to water, rather than those which act by the abundance or 

 deficiency of those substances which are the food of plants. An 

 analynis which .-hall fully explain the fertility of a soil, must tell us 

 ii..t ..nly the quantity and condition of the gand, and clay, and lime, 

 and humus of a soil, but also the quantities of potash, soda, magnesia, 

 phosphoric acid, sulphuric acid, chlorine, soluble silicates, and ammonia 

 present in it. It is the presence, whether of humus or any other 

 ingredient which shall, by the operation of atmospheric solvents, gra- 

 dually yield to the growing plants such substances an these, which 

 determines the fertility or infertility of a soil. And since the publi- 

 cation of Licbig's writings on Agricultural Chemistry, the importance 

 once attributed to the presence of mere humus in the soil aa the true 

 index of its fertility, has disappeared. It is now known that the 

 decaying vegetable matter of a soil ia of service, not only as itself 

 yielding, by its gradual destruction, food for plants, but also, and even 

 chiefly, by its action as a ferment on the stores of food laid up in the 

 clays and purely mineral portions of the soil, as well as by the facilities 

 i if access given, by its mixture with these mineral matters, to the air 

 and water of the atmosphere, which by their disintegrating and decom- 



posing operations, let loon from these stores much that is naturally 

 locked up and useless. 



Of course, the depth of the soil and the nature of the subsoil greatly 

 affect the value of land. However rich it may be, if there is only a 

 thin layer of good soil over a sharp gravel or a wet clay, it cai 

 be very productive : in the first case, it will be parched in dry weather; 

 and in the latter, converted into mud by even 1 continued rain. If tin- 

 Mil ,~.il be loam or chalk, six inches of good soil will be sul) 

 With a foot of good soil, the subsoil is of little consequence, provided 

 it lie dry, and the water can find a ready outlet. The best alluvial 

 soils are generally deep ; the chalky, shallow. It in of importance to ob- 

 nerve, that not only does fertility di>]>en<l on the presence in the soil of 

 abundant food for the growth of plant*, but also on there being suffi- 

 cient freedom of inasage through it for the rain-water, which, as it 

 traverses the soil, dissolves out this food, and takes it by the roots of 

 plants, thus giving them an opportunity of absorbing it, A soil in 

 which water is stagnant, or through which it cannot paw, is neces- 

 sarily barren ; the plants which would grow upon it starve, because 

 there can be no circulation through it of dissolved food, no opportunity 

 tli<-ref"re of supplying the roots with fresh supplies of nourishment. 

 It is to its thus providing for the circulation through the soil of food 

 for plants, that the fertilimng influence of land drainage is chiefly due ; 

 but the reader must be referred to the article DBAINAGE for a fuller 

 explanation of its operation. 



The exposure, with respect to 'the sun, and the declivity of the 

 ground, are very important circumstances in the value of land ; they 

 are indeed equivalent to an actual difference in the climate. A gentle 

 declivity towards the south, and a shelter against cold winds, may 

 make as great a difference as several degrees of latitude ; and in com- 

 paring the value of similar lands in different climates, the average heat 

 and moisture in each must be accurately known. A soil very fertile in 

 the south of Europe may be very unproductive in Kngland; and a 

 li -lit soil of some value in the west of Scotland, might be absolutely 

 barren in Italy or Spain. 



Of the Cultiration of the Soil The better the soil, the less cultiva- 

 tion it requires to produce tolerable crops ; hence, where the land is 

 very rich, we find in general a slovenly culture ; where the ground in 

 less productive, more labour and skill are applied to compensate for 

 the want of natural fertility. The simplest cultivation is that of the 

 spade, the hoe, and the rake, and on a email scale it is the bent ; but 

 spade husbandry cannot be carried to a great extent without employ- 

 ing more hands than can be spared from other occupations. The 

 plough, drawn by oxen or horses, is the chief instrument of tillage, 

 and has been so in all ages and nations of whii -li we li.ive any records. 

 Its general form is familiar to every one, and requires no minute 

 description. The various kinds of ploughs in use at different times, 

 and the improvements which have been made, and are attempted, daily, 

 will be noticed in a separate article. [PLOUGH.] Suffice it to say at 

 present, that a plough should as much as possible imitate the work 

 done with a spade. It should cut a slice from the land by its coulter 

 (a) vertically, and by the share (b) horizontally lift it up, and tin n it 

 quite over by means of the mould-board (c) ; and the art of the plough- 



m, ThteoaltOT. 



, Tb point at Ih* tkai*. 



t, Tb.moold-bo.rd. 



*, To* beau. 



[PlrntT'i Swing, Plough.] 



r, The chain by which it It drwn ; f, a long Iron link to which the chain In Axed, 



which can be hooked In any of tho notches, //, altering the line of draught. 

 A A, The handln, or ttllti. 

 i, The hook to draw by. 



i in doing this perfectly, and with imch a depth and width 

 M suit UM (oil and the intended purpose. In rich mellow soils a 

 ptaffaeH field should differ little from a garden dug with the spade. 

 In tenacious toils, the slice will be continued without breaking, espe- 

 cially if bound by the fibres and rooto of plant* ; the whole surface will 

 be turned over, and the mot* exposed to the air : it is of great mn- 

 WBO* that each slice bo of the SUM width and thickness, and the 

 i of it perfectly ttraight and parallel. Tho plane of the coulter 



must be perfectly vertical, and that of the share horizontal, in order 

 that the bottom of the furrow may be level, without hollows or bauUv, 

 which arc irregularities produced by the rii-ing or Kinking of the plough, 

 or inclining it to either nidc. The andents were very particular in 

 this respect, and reoomni' ml"l wanding the earth with a sharp stake, 

 to ancert.-iiu wlu-tlicr tin- ploui.-liMi.in 1ml done hid duty. Tliero ore 

 various modes of ploughing laml. ritli.-r .pm, Hit, or in lantft or 

 BtitchM, as they arc c.JKd in Kngland, and, in Scotland ripj*, thftt is 



