322 QUEENSLAND AGRICULTURAL JOURNAL. [1 Ocr., 1897. 
(6) Fertilisation has an important bearing on disease. — 
(7) “Die-back,” a serious malady, is in all probability the result of over- 
feeding with nitrogenous manures from organic sources. These manures, 
if used at all, should be applied with great caution. ‘ 
(8) Foot-rot, although not primarily due to improper methods of fertilisation, 
is no doubt considerably influenced by this cause. 
(9) Insect diseases are also apparently influenced by the use of fertilisers, 
organic manures rendering the trees more liable to injury from this source 
than chemical fertilisers. 
It is important to mention that the orange soils in Florida are “sandy and. 
sterile.” 
Naturally, the experiments made by Mr. Webber are of very great value, and it 
would be well to have similar ones carried out in the orange-growing districts of our 
colonies. I believe that many differences in results would be found in the effects of 
manures to Australian soils. I may state that I have seen an orange orchard ruined by 
very heavy applications oforganic manure from a slaughter-house; and Lhave seen stable 
manure applied to others with marked success. The soil in most instances being clay- 
loam over shale. I am inclined to think that, in the volcanic soils such as we have in 
the Richmond River district, New South Wales, and very similar soils in Queensland, 
such as that in the neighbourhood of Bundaberg, organic manures will be advan- 
, tageous, particularly green manures such as the cow-pea. The farm manager, Mr. 
McKeown, at the Wollongbar Experimental Farm, Richmond River, has been making 
experiments with the cow-pea, especially for oranges, for some time past, and so far 
the very young trees, which have only ‘been ee about three years, are thriving 
satisfactorily, and some of them have produced early and excellent fruit. For one thing, 
the soil there is very deficient in vegetable matter, and for another the cow-peas are 
grown as a green mulch. I merely mention this little experiment for what it is worth 
at present. I think a green summer mulch will prove very advantageous. 
The mechanical condition of many of our soils would be greatly improved by the 
application of dung or the ploughing in of green crops, and their power of retaining 
moisture would be immensely increased. ‘The effect also of these manures in liberating 
mae aa plant food during their decomposition will be found, I believe, to be very 
marked. 
Another well-known and popular manure is bone meal, or bone dust as it is 
generally termed. This has been and is used in orchards without any mixture with 
other manures. 
An analysis of good bone meal shows that it contains the following percentages of 
various substances :— 
Moisture... an an {sek 
Organic matter... . OL12 Containing nitrogen 4°06, equal to 
ammonia 4°93, 
Lime phosphate... ... 49°43 
Silica ae ats ao lal 
Calcium sulphate ... ... trace (Gypsum) 
Carbonate of lime ... BPE OiDO 
100'00 
Its chief value lies in the large percentage of phosphate of lime; but the 
nitrogen must also be considered of value. 
Tt will be seen from this analysis that bone dust contains no potash, and as T have ~ 
already indicated, potash plays a most important part in the life of fruit plants and 
in the formation of fruits, therefore if the soil of an orchard contains but little potash, 
and this orchard be manured year after year with bone dust alone, the little potash in 
the soil is likely to be very soon exhausted. I have seen many orchards manured year 
after year with bone dust alone, and the evil effects of such applications have been 
very apparent in course of time. Ihaye used bone dust frequently for various 
purposes, on somewhat heavy soils, and fround that it had a great tendency to 
consolidate and cake the soil, and I may state here that I found artificial or 
chemical manures generally to have this effect. I strongly advise anyone who uses bone 
dust to purchase it subject to analysis, for this manure can be very easily adulterated, 
an it is not profitable to purchase sand and other useless rubbish at the price of good 
one dust. 
Sulphate of ammonia is another manure well known in the colonies, and fre- 
quently used in orchards. Everyone who uses this chemical manure, should thoroughly 
understand that itis useful for one substance only, and that is nitrogen. He who 
uses it should also understand that after application the nitrogen soon becomes soluble 
