188 QUEENSLAND AGRICULTURAL JOURNAL. [1 Mar., 1902. 
It may be argued that a moderately fertile soil containing, say— 
1 per mille of nitrogen 
1 per mille of phosphorie acid, 
2 per mille of potash, 
50 per mille of lime, 
has practically an inexhaustible supply of those elements, inasmuch as 1 acre of 
that soil 6 inches deep contains nearly 1 ton each of nitrogen and phosphoric 
acid, 2 tons of potash, and 50 tons of lime. 
But this is a mistake ; it would appear that if the elements fall below a 
certain standard most crops and fruit trees are unable then to absorb the amount 
necessary for maintaining their vigour and cropping powers. It is an 
undeniable fact that fruit trees will be sickly and unable to bear anything of a 
crop in an exhausted soil which yet contains theoretically sufficient elements of 
fertility to keep them in good health for another twenty years. 
So soon then as vines begin to show that the reserve in the soil is below 
their requirements manuring is advisable. Chemical analysis will tell which 
particular constituent or constituents are wanting, but without resorting to 
analysis experience has taught us that if the leaves are not dark-green in colour, 
but of a decided yellowish tint, then nitrogen is required. The vigneron must, 
however, use his judgment as to whether bad drainage may not be the cause of 
this appearance. 
A deficiency of phosphoric acid is indicated by small bunches and berries 
with badly developed seeds. A deficiency of potash is shown by poor fruit and 
stunted thin canes. <A. soil rich in nitrogen which will cause a luxuriant growth 
of wood and leaf may be deficient either in phosphoric acid or potash, and when 
this is the case the crop will be out of proportion to the vigour of the vine. 
Moreover, it has been proved repeatedly that vines growing in such a soil are 
more readily attacked by fungoid diseases, and the grapes are more prone to 
rot in wet weather; the wine made from those grapes is also more liable to 
become diseased than that made from soils where potash or phosphoric acid is 
abundant. A small yearly addition to the soil of the deficient element will be 
amply repaid by the increased crop and improved resistant powers of the vine 
to fungus attacks. Grapes grown in soils containing a sufficiency of phosphoric 
acid and potash will always make a better wine than those from a soil deficient 
in these elements. An extended analysis of the finest growths of French wines 
proved that the quality decreased in proportion to the decrease of the amount 
of those two minerals in the wine. - 
It follows then that when manuring vines, more attention should be paid 
-to the use of potash and phosphoric acid than to nitrogen; the soil is always 
absorbing nitrogen from the atmosphere if it is kept in good cultivation and in 
fine tilth, and it also receives some in the rainfall, in small but appreciable 
uantities ; whereas potash and phosphoric acid are always being removed 
rom the soil by crops, but none is returned naturally. It does not follow, how- 
ever, that nitrogen is to be neglected in the fertiliser. A fair proportion of 
the elements to be used in general manuring would be 40 parts of potash 
to 60 of phosphoric acid and 60 of nitrogen, but of course, these pro- 
portions are very variable according to the composition and physical condition 
of the soil to be fertilised. Lime is a most necessary element to the soil and 
should always be added where it is deficient, as it is not only required by the 
vine but it is necessary to the nitrification of ammonia compounds before 
they can be utilised by plants and to the decomposition of other chemical 
compounds in the soil. The use of lime is followed by increased vigour and’ 
fruitfulness of the vines, but the soil is impoverished to the same extent, so 
that the employment of lime should always be accompanied. by that of other 
‘fertilisers. It is well, however, not to put them on at the same time, or there 
may be a loss of nitrogen. Lime, moreover, acts most beneficially in a 
mechanical manner as it renders sticky soils more porous; it would prove of 
greatiservice on the heavy black and chocolate soils which abound in Queens- 
jJand. Plaster or gypsum is an excellent form of lime manure, but it is too 
costly in this State to be available. 
