1 Ocr., 1899.] QUEENSLAND AGRICULTURAL JOURNAL. 379 
' Cancrum (Lime). 
Lime is essential to the growth of all plants, and constitutes from about 
4 per cent. of the total ash, in the case of the apple, to as high as 80 per cent. 
in theash of Californian lemons—the orange requiring rather less, about 23 per 
cent. These percentages refer to the fruit, itself, but the wood of some of our 
fruit trees, notably the olive, contains a very much greater proportion, for, 
whereas the proportion of lime in the fruit of the olive is only about 16 per 
cent. of the total ash, that of the wood is about 6O per vent. Considerable 
quantities of lime are also required for the successful growth of peas, beans, 
clovers, lucerne, potatoes, wheat, and other cereals. dn the case of pulses, it and 
potash may be considered to be the dominant ingredients. Soils that produce 
white clover, burr clover, and variegated thistles in profusion are rich in lime, 
as also is water that grows a quantity of watercress. In the Western portions 
of the colony land growing gidya is also rich in lime, the ash of this tree 
containing over 90 per cent. Most of our soils contain lime in sufficient 
quantity for all crops, but there are others again in which there is a marked 
gitceees Where these latter occur, lime must be applied as a manure, and 
for this purpose from 1 ton to 13 tons per acre is sufficient; but if, in addition 
to the soil being deficient in lime, it is sour and unworkable, a muth larger 
wnount—from 4 to 6 tons to the acre-—-must be applied. Lime owes its 
efficiency not only to its value as a manure but more especially to the cffect it 
has on the soil of sweetening it, and rendering it more friable, and consequently 
more easily worked; and in addition it acts beneficially in that it renders 7 
portion of the unavailable potaxh of the soil available for plant food. It also 
acts on the injurious salts of iron present in the soll—oxidixes them, converting 
them into iron-rust, which, except when it is present in the soil in any excessive 
quantities, is not injurious to vegetation. Its sweetening effect is due to the 
fact that when it comes in contact with the free acids in the soil it neutralises 
them. If the lime is required by the soil to supply its natural deficiency, it may 
be applied in the form of chalk—ground shells, or coral, or any other form of 
sarbonate of lime—or as caustic lime, formed by the burnine of any form of 
carbonate of lime; butif its mechanical, rather than its manurial, qualities are 
required, then it should always be applied in the form of hydrate of lime, 
which is formed by allowing the caustic lime to slack in the field or orchard in 
the following manner :—Heaps of caustic lime, containing three to five bushels, 
are placed at convenient distances for distribution, and are covered with 
6 inches of soil so as to exclude the air. The heaps are allowed to remain two 
weeks or longer, when the lime will be found to be in a fine powder and fit for 
spreading. Lime applied in this form has a much more beneficial effect in 
breaking up and sweetening the soil than if applied in an air-slacked condition ; 
as air-slacked lime is simply carbonate of lime, its original condition before 
burning. Lime is best applied during the autumn or winter, and it should be 
evenly distributed over the land and lightly ploughed in. Tf ploughed in too 
deeply, a quantity is sure to be lost, as it ulways tends to sink in the soil. 
Lime should always be used by itself, as if uséd in conjunction with other 
manure it will cause the whole of the nitrogen present in the manure to be 
thrown off in the form of ammonia gas, and so become lost. Where the land is 
regularly manured with bonedust or superphosphates, there is always enough 
lime present in these manures to meet the requirements of any crop without 
Special recourse being had to liming by itself, but where the soil is naturally 
deficient in lime a good manuring of lime should be given first, and then 
subsequent manurings of bones or superphosphates will generally suffice without 
wy further application. Lime is obtained by plants in the form of carbonate, 
which is dissolved by water containing carbon di-oxide in solution, and is thus 
absorbed by the roots. 
I have mentioned the large proportion of lime found in the ash of the 
wood and fruit of the olive, showing that this element is essential to the growth 
of this particular fruit, and this is clearly exemplified by the growth olives are 
making both at the Westbrook and Hermitage Mxperiment Farms on the 
