May 2, 1904.] Supplement to the " Tropical Agriculfunst." 
795 
high on one acre produced 168 lb. nitrogen, equal 
50 £5 worth of nitrogenous manutes. Catch 
crops or cover crops are also a distinct gain to 
exhausted soil;'. Take such a crop ns rape, which 
can be grown during the winter instead of 
allowing the ground to lie idle or growing weeds. 
It breaks up the subsoil and admits air. It 
brings up from below stores of potash and phos- 
phoric ncid, and leaves them on the surface for 
the next crop. The green herbage can be fed 
off with sheep, the most useful of domestic 
animals in returning nitrogen and other valuable 
constituents to the soil in their excreta. Such 
a crop prevents winter rains washing or leaching 
away into drains, gullies, creeks and rivers, large 
stores of soluble plant-food. The roots turned in 
add to the humus of the soil, and act as a mulch, 
" Never let the soil lie idle "is a sound axiom. 
Loose soils are made firmer, and more retentive, 
sandy soils are built up and made more fertile, 
clay soils become lighter and more friable. Feed 
off catch crops with sheep, pigs, or cows, and 
return to the soil a large proportion of the 
manure. Every crop sold off the farm meaas 
a dead loss of fertility. The mechanical, bac- 
terial, and fertile condition of the soil is always 
benefited by catch, cover, or green manure crops 
— for the growth of which we have a suitable 
climate. In leguminous crops we have absolute 
evidence of the presence of myriads of bacteria 
in the nodules or warty excrescences on the 
roots of the various plauts— their functions being 
to throw off certain compounds which combine 
with others to release the surrounding insoluble 
plant-food. Any crop or weeds will net as a green 
manure. The aim is to keep some kind of crops 
on your land all the time, and to change it from 
crops that rob the land of fertility to those which 
are soil renovators, and increase its plant food. 
You may be in a position to economically supply 
the requisite manure, or the soil may be rich 
enough to stand cropping for years ; in such cases 
a rotation is not indicated. The main object is 
to arrange a aeries of crops in rotation to main- 
tain fertility. The law of rotation, or the class 
of crop, is determined largely by climatic con- 
ditions and soils. Cowpea is a good crop, to be 
followed by maize, and this followed by a root 
crop. Wheat sown after turnips or potatoes is 
always likely to yield more heavily. The object 
throughout is never to allow two crops following 
each other which require the same ingredients or 
fertilisers. Follow a deep-rooted crop with a 
surface-feeding plant. Alternating the crops on 
such lines enos in augmented fertility. A Dutch 
farmer's wealth is estimated by the number of 
windmills he owns, but the wealth of a German 
farmer is assessed by the size of his manure heap. 
Farmyard manure is the basis of all effective 
fertility, It is lasting in character, provides 
nitrogen, phosphoric ncid, potash and organic 
matter, retains moisture, and conveys inuumer- 
able bacteria to the soil. There is nothiug on 
the farm with a more varied value, which is often 
determined by the class of animal housed, the 
feed, the litter used, and the methods adopted 
in collecting and conserving the manure. In 
every instance chemical analysis has shown that 
the liquid manures are more than double the 
value of the solids from amanurial point of view; 
they are more rapid in action, and contain more 
soluble plant-food. Since better knowledge of 
the fermentative processes has been acquired it 
is now known that the best practice is to combine 
the liquids with the solids. All manures should 
be placed in a covered shed with a solid floor, 
stiff clay or cement, the solids to be intimately 
associated with the liquids. All refuse or manure 
from stables, cow bails, and pig styes to be 
collected as rapidly as possible, especially horse 
manure. IE there be no suitable means of pro- 
tecting it from the weather until the fermentative 
changes have been secured, then the sooner it 
is put on to the land the better. One ton of 
farmyard manure contains approximately : 8 lb. 
nitrogen, 6 lb, potash, 6 lb. phosphoric acid, 
A ton of ordinary farm-yard manure will contain 
fertilising elements equal to from 12s, to 153. 
worth of artificial fertilisers. The old Scotch 
system of conserving farm-yard manure would do 
well in cold countries where the cattle are housed. 
Here, however, with our warm climate and need 
for sanitary conditions, the manure is best con- 
served in a sheltered place or placed quickly on 
the land. The nitrogen in farm-yard manure 
does not supply all that is needed, and this may 
be balanced or supplied in artificial form. In 
this rapid and cursory review of the Food of 
Crops I am unable to include the question of 
the use and abuse of chemical or artificial or 
commercial manures ; it would require a separate 
lecture to deal with a subject of such vast 
importance. Further, the question of the appli- 
cation of bacteria to every day use on the farm 
needs further elucidation, and if thought desir- 
able 1 will gladly take up these subjects on 
future occasions. The subject of Food for Crops 
in our warm and exhausting climate is one that 
demands serious consideration. The wondrous 
power in the hands of our agriculturists, if intelli- 
gently applied, must add to the sum of our food 
products, raise the general tone of agricultural 
life', increase the attractiveness of rural occupation, 
and make farmers wiser and wealteier men, 
— Agricultural Gazette, N.S. W. 
DISEASES OF FARM STOCK AND THEIR 
PREVENTION, 
By D, Hutcheon, M.R.C.V.S., 
Colonial Veterinary Surgeon, Cape Colony, 
South Africa ha? acquired an unenviable reputa- 
tion with respect to the number and virulence of 
the diseases which affect its farm stock. It is 
some consolation, however, to reflect that a very 
large percentage of these diseases are not indige- 
nous to the country, but have been intro- 
duced either from Europe or from North- 
Eist Africa, There is very little doubt that 
glanders, strangles, epizootic lymphangitis — 
and even influenza — of the horse have been 
imported iuto South Africa, and did not originate 
from any local conditions existing here. It is the 
saa'3 with respect to the following diseases of 
