160 Commercial Gardening 



of " liming " the soil has largely gone out of fashion. Market gardeners 

 and farmers, however, appear to be again waking up to the importance 

 of lime, not only as a cheap and excellent manure, but also as a powerful 

 check to " clubroot " in Cabbage crops, to " eelworm " in Cucumbers and 

 Tomatoes and other crops, and by keeping many other pests at bay. 

 The old saying that 



" Lime and lime without manure 

 Makes both farm and farmer poor ", 



is perfectly true, and it illustrates the wisdom of our forefathers. Owing 

 to chemical actions set up in the soil by the presence of lime, organic 

 matter like stable manure is rapidly converted into such a state that its 

 nitrates, potash, phosphoric acid, &c., are soon liberated and absorbed. 

 Consequently, unless manure is added regularly to the soil, it would soon 

 be brought into an impoverished state by the continual application of 

 lime alone. 



In a state of nature lime does not occur in a free state. It is usually 

 combined with carbonic acid, and in many parts is found in abundance as 

 carbonate of lime the commonest forms of which are limestone and chalk. 

 Pure carbonate of lime is composed of 53'6 per cent of lime and 437 per 

 cent of carbonic acid. When burnt in a kiln the carbonic acid gas is 

 driven off into the atmosphere, and the residue quicklime is formed. 

 This quicklime absorbs water greedily, and in coming in contact with it 

 becomes " slaked ". This is then called hydrate of lime, or, more properly, 

 slaked lime. If left exposed to the air the slaked lime gradually loses 

 its water, and absorbs carbonic acid gas instead. It thus becomes carbonate 

 of lime once more. 



In wet, heavy, clayey soils the application of "quicklime" or caustic 

 lime to the surface is of the utmost benefit after the soil has been turned 

 up with the spade, fork, or plough. The quicklime readily absorbs the 

 surrounding moisture, generates great heat, and brings the soil into a 

 drier and better condition for working. For heavy land there is nothing 

 better than a good dressing of quicklime to bring it into a state of cultiva- 

 tion. From 30 to 200 bus. per acre is applied according to circumstances. 



Chalk, or carbonate of lime, is also an excellent dressing for most farms 

 and gardens that receive liberal dressings of manure. The latter is apt 

 to generate acidity if the soil has not been deeply dug or trenched, and 

 this acidity in turn is apt to produce clubbing of Cabbage crops, eelworm, 

 and other plant diseases, owing to the lack of oxygen in the soil. Lime in 

 any form helps to check this state of affairs. 



Marl, which is a mixture of clay and chalk in varying proportions, 

 is a useful adjunct to light or gravelly soils, because it makes the particles 

 more tenacious, and this enables the soil to hold manures better. There 

 are several kinds of marl, such as clay marl, sandy marl, chalk marl, 

 slaty or stony marl, shell marl, and peaty marl all containing a certain 

 quantity of calcareous matter. 



