1 Fesz., 1902.] QUEENSLAND AGRICULTURAL JOURNAL. 77 
added more tea to it. In the same way, if you only give water to a plant and 
do not supply the other plant food which successive crops have taken out of 
the soil, the result will be that you will have no crops, because all the plant 
food they require has become exhausted, and the soil is said to be BARREN, 
STERILE, or HUNGRY. 
In a vast country like Australia there is such a quantity of rich, new 
land—virgin soil, as it is called—that often it suits the farmer better to plough 
up new lands than to go to the trouble of refertilising the old land ; but where 
there is a close settlement of farmers such a course would not be practicable. 
The old land has to be esa again and again, and therefore the farmer has 
to resort to some means of restoring the fertility of his land, and this he does 
in several ways. J'irst, by deep cultivation; secondly, by applying suitable 
manure; and, thirdly, by irrigation or by artificially supplying any lack of 
moisture. You have, I daresay, heard of the beautiful farms of Great Britain 
and France and other European countries. These farms have been cultivated,’ 
many of them, for over 1,000 years, and yet they produce to-day far larger 
crops than they did when William the Conqueror landed in England in 1066 
A.D. This wonderful fertility has been kept up during all these years by the 
help of manure, cultivation, and by the “Rorarron or crops” which I have 
told you about in previous lessons, and of which we shall again speak later on. 
But farming nowadays is carried on in a much more scientific manner than it 
was in the days of our forefathers, and we have to thank the scientific chemist 
for teaching us how to apply exactly the kinds and quantities of manures 
required by different plants. 
The best method of applying the needful plant food in the shape of 
manure is one of the most essential studies to which the farmer should devote 
himself. 
You have been told what are the various constituents which go to build up 
a plant, and that these are supplied from two sources—the air and the soil. If 
the soil is poor in any one or more of these constituents, that one or more 
must.be put into it by some means, and that means was for a long series of 
years farmyard manure. We will now further consider manures both natural 
and artificial. 
Farmyarp Manure consists of the solid and liquid excrement of domestic 
farm animals, and is usually mixed with the straw or other bedding supplied to 
the cattle, horses, and pigs when they are housed in byres, stables, and styes. 
Tt contains everything that is required by cultivated crops to bring them to 
perfection. It also has the advantage of containing organic and inorganic 
compounds which do not all dissolye in the same manner or at the same time, 
and this is one reason why, farmyard manure is better than natural manures 
like the earth called guano or nitrate of soda, which are obtained in vast quan- 
tities from beds on the west coast of South America and in some other 
countries, as we shall see by and by. The farmyard manure improves the 
hysical condition of the soil, as well as supplying all the plant food demanded 
ee farm crops, because it leaves all that is not immediately required by the first 
crop sown after it has been applied retained in the soil for the benefit of 
future crops. 
One of the great advantages of supplying plenty of straw bedding to 
stabled animals is that it soaks up and retains the liquid portion of the excre- 
ment which contains the alkaline salts and nitrogenous matter. Thus the urine 
is by far the most valuable part of the manure. The solid parts contain phos- 
phoric acid, lime, magnesia, and silica, and scarcely any nitrogen The in- 
organic constituents of farmyard manure are phosphoric acid, oxide of iron, 
lime, potash, soda, magnesia, chlorine, and carbonic acid. Now, if you look at 
an analysis of the ashes of a part of a burnt crop, you will see that all these 
ingredients are present in the ashes. Nitrogenous compounds of different 
kinds are the organic constituents of farmyard manure, and these, by decom- 
posing, produce ammonia, which is, as you know, a very valuable plant food. 
