AGRICULTURE. 



Unless they are managed so as to allow the frost 

 of winter to assist in their pulverisation, it is 

 often a most difficult matter to effect this by all 

 the implements at the command of the farmer. 

 Drainage, however, has done a great deal towards 

 rendering this class more easily cultivated ; and 

 at present, they are made to produce excellent 

 green crops in ordinary years. Clover and arti- 

 ficial grasses produce heavy crops of hay on clay 

 soils, but the pasture is generally inferior, as the 

 treading of stock seems to be adverse to the 

 healthy growth of grasses on these soils. 



Chalky soils have a large proportion of cal- 

 careous matter in their composition. The valleys 

 of the chalk districts in England, however, usually 

 abound in clay, and the soil is particularly tena- 

 cious. The chalk loams are well suited for the 

 growth of all kinds of crops, more especially of 

 wheat, barley, clover, and turnips. These are the 

 only soils upon which sainfoin and lucern thrive. 



Alluvial soils are composed of the finest par- 

 ticles of earth which have been washed by floods 

 from the upper part of the courses of rivers. 

 They have generally a rich level surface, and 

 being deep, yield excellent crops of wheat, oats, 

 barley, beans, potatoes, and clover. To manage 

 these lands well, the farmer must undergo a 

 thorough training, so as to enable him to cultivate 

 them properly, with the least expenditure of 

 labour. A celebrated soil from Ormiston, in 

 East Lothian, which contained more than half 

 its weight of finely divided matter, absorbed, in 

 Sir Humphry Davy's experiments, six times more 

 water than the soil from Bagshot Heath. 



Varieties of soils, however, are as numerous as 

 the rocks from which they have been formed. 

 The adaptation of the different varieties of soil for 

 the growth of particular crops, will be best illus- 

 trated when we come to consider the culture of 

 the particular crops. 



THE CHEMICAL CONDITION OF SOILS. 



In nature, we find the earth covered by a vege- 

 tation that thrives upon the same spots for ages. 

 But it is well known that if some of our cultivated 

 crops are frequently repeated on the same soils, 

 they become a prey to different kinds of diseases. 

 In nature, those plants which are fitted to the 

 chemical condition of the soil, take possession of 

 it ; but man endeavours to make certain plants 

 grow upon every variety of soil. 



It is well known that sainfoin and lucern will 

 not thrive upon land unless it contains a large 

 quantity of calcareous matter. Now, the analysis 

 of the ashes of these plants does not indicate that 

 either of them requires more lime for building up 

 its vegetable structure, than some others that 

 thrive upon soils containing but a small quantity of 

 calcareous matter. Turnips, it is well known, are 

 subject to finger-and-toe, a disease for which a 

 liberal application of lime to the soil will act as a 

 preventive. That the lime in this case, however, 

 does not act by merely affording lime as a con- 

 stituent to the crop, is evident from the fact, that 

 it does not cure finger-and-toe when applied, like 

 other manures, at the time the crop is sown. It 

 must be applied for a year or two previous, that it 

 may have time to produce a certain chemical 

 effect upon the land. The particular action in 

 this case, we have been led to believe, consists in 



the lime directing or controlling the particular 

 decomposition that all vegetable matter is under- 

 going in the soil. The particular products that an 

 unlimed soil often yields interfere with the healthy 

 action of the absorbing powers of the roots of 

 plants, which are thereby prevented from taking 

 up a due supply of the earthy matters. The 

 deficiency of these matters induces a corrupt state 

 of the vegetable juices, which thus become the 

 nidus for particular kinds of insects. It has 

 always appeared to us that the insects are not the 

 cause of the disease of finger-and-toe or anbury, 

 as Professor Buckman supposes, but a conse- 

 quence of diseased conditions. 



Vegetable physiologists who suppose that plants 

 absorb their food mechanically along with water, 

 are evidently at fault The process is apparently 

 a chemical one, similar to that which takes place 

 when leaves absorb carbonic acid and ammonia 

 from the atmosphere. But, more than this, we 

 have long been led to the conclusion, before being 

 aware of Gazzeri's experiments, that roots virtually 

 exercise, by their contact with solid matter, an 

 incontestable action in imparting solubility to it. 



In order that the roots of plants may exercise 

 on the substances constituting their food an 

 absorbent action, which is equivalent to a power 

 of selection, they must be placed in a medium 

 capable of maintaining their healthy functions. 



This peculiar chemical condition of soils, which 

 is a quality over and above the mere presence of 

 the constituents of plants, is a highly important 

 one. Finger-and-toe in turnips, clover-sickness, 

 the dying out of certain grasses in particular soils, 

 and many phenomena in the vegetable world, 

 arrange themselves for elucidation under this 

 head. 



The particular quality of soils, also, which prac- 

 tical men distinguish by the terms ' sharp ' and 

 'deaf/ arises from their chemical condition. It 

 ought to be borne in mind that the repetition of a 

 particular crop on any soil does not necessarily 

 unfit the soil for producing it in a healthy state, if 

 the chemical conditions are favourable. In many 

 soils deficient in calcareous matter, the quantity of 

 crude vegetable matter which turnips leave by 

 their decaying roots, impairs the healthy functions 

 of their roots when too frequently repeated. Lime 

 cures this quality of the land, by correcting or 

 neutralising the decomposing matters left in the 

 soiL One of the most interesting facts elicited by 

 Mr Lawes in his experiments at Rothamsted is, 

 that he has raised turnips on the same land with 

 superphosphate of lime for eight or ten years in 

 succession. The American farmers also sow 

 clover every other year, but do not complain of 

 clover-sickness. Clover-sickness and finger-and- 

 toe, however, sometimes arise from an actual 

 deficiency in the soil of the substances found in 

 the ashes of the plants. 



CLIMATE OF GREAT BRITAIN. 



The effects of climate on crops and systems of 

 farming will be best treated when considering 

 the culture of particular crops, and the practical 

 economy of rotations. Under the present head, 

 we shall confine ourselves to some general re- 

 marks on temperature, rains, and evaporation. 



However useful the means of monthly tempera- 

 ture may be for some purposes, they are of little 



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