Nov. 1, 1894.] Supplement to the " Tropical Agriculturist." 
355 
farmyard manure can scarcely be looked upon as 
an absolute essential, inasmuch as it is a bye-pro- 
duct of the farm, and will always continue to be 
so, a thorough knowledge of its nature and com- 
position must ever remain for the farmer and 
agricultural st udent of the highest importance. 
" The question of the fertility of the soil is a wide 
and complex one. It depends on many and 
various circumstances and conditions. Apart alto- 
gether from the influence exerted by climate, lati- 
tude, altitude, and exposure, it may be said to be 
dependent on properties of a physical, chemical and 
biological nature. 
"The first class of properties consist of the ab- 
sorptive and retentive powers of the soil for water, 
gases, and heat. These properties depend on the 
proportion in which the so-called rjroxirnate con- 
stituents of a soil are present — such as gravel, sand, 
clay, humus, and lime — as well as on the size of 
the soil particles, and on their colour The chemi- 
cal composition of the soil furnishes, however, the 
most important source of fertility. As the plant 
has to derive a portion of its food from the soil, 
the possession by the latter of the ingredients 
constituting this food is a fundamental con- 
dition of plant growth. A very small portion 
of the soil is directly concerned in promoting 
growth. , Some of the necessary ingredients 
are apt to be lacking in sufficient amount, 
and it is in making good this want that the 
chief function of manures consists. The sub- 
stances in which most soils are generally found 
to be deficient are nitrogen, phosphoric acid, and 
potash. Manures, therefore, are chiefly applied to 
make good this deficiency. While, however, this 
is so, manures, it must not be lost sight of, 
perform other and important functions, and may 
be of value not merely because they supply to 
the soil nitrogen, phosphoric acid, or potash, 
but also because they exercise some influence 
on the soil's mechanical properties, or it may 
be, in preparing for the plants' use inert fertilising 
substances. The functions of a manure, there- 
fore, may be very varied, and no manure ex- 
emplifies this to a greater extent than farmyard 
manure." 
In another column we reproduce the remarks 
made by the Director of Public Instruction (in 
his Administration Report for last year) on the pro- 
posed School of Forestry. We may mention that 
some start has been made in the development of 
this scheme already. The Conservator of Forests 
has been sending a number of written "lectures" 
to be given to the students of the School of 
Agriculture, and has himself been over at the 
school to explain and illustrate the substance of 
these lectures. The great desideratum in a forestry 
course (as, we believe, Mr. Broun has himself 
Slid in his own Administration Report) is the 
arrangement by which the students may be given 
a practical training in the subject. This as well 
as the arrangement for teaching the auxiliary sub- 
jects allied to Forestry have as yet to be worked 
out and to receive the sanction of Government. 
We trust that the scheme in its fully-developed 
form will soon come into working, for, despite the 
opinion of some, who cannot surely fully un- 
derstand the full signilicance of the term forest con+ 
eerwncy and the work it involves, we beiieve I lint 
there much to be done in the way of in-tilling a 
technical knowledge of our tropical forests into the 
minds of those who seek admission into the Forest 
Department, and that it would be a penny-wise 
policy that would refuse the aid that is necessary 
to bring our forests under scientific treatment 
by experts. 
FODDER CROPS AND CATTLE-KEEPING 
IN CEYLON. — -IV. 
In the previous instalments of this paper two 
of the important fodder crops grown in the 
Island, viz., Guinea grass and Mauritius grass, 
have been dealt with. These two have already 
gained ground here, and we are more or less fami- 
liar with them. It has to be noted, however, 
that the above grasses do not necessarily thrive 
in all descriptions of soils, nor under all cir- 
cumstances ; and therefore other species of fodder 
crops, grown successfully in various tropical and 
sub-tropical countries, deserves attention in this 
country, as their introduction would tend to an 
increase of our fodder supply. The introduction 
of a new and little known crop is beset with 
many preliminary difficulties, and takes much 
time before it meets with any degree of favour. 
Two crops which are extensively grown in India 
for fodder purposes deserve special notice. These 
are the lucerne plant Medicago satica and the 
Jowari, Sorghum vulgare. 
Lucerne thrives in good loamy soils and has 
to be well cultivated if a profitable crop is to 
be obtained. Being a leguminous plant it is 
especially partial to soils containing a fair per- 
centage of lime. Before a crop could be raised 
the land requires very careful preparation. The 
seed is generally sown in shallow furrows two 
inches deep and lightly covered up. The furrows 
are made a foot apart and kept carefully weededi 
The land requires artificial irrigation when there 
is not sufficient rain. The plants grow up in 
two months and should be cut just before tney 
commence flowering. Under good cultivation, a 
plot of lucerne could be kept up for years 
with proper care and manuring and a cutting 
obtained nearly every six weeks. In this 
manner an acre of land yields a large quantity 
of a very nutritious and wholesome fodder. The 
amount of produce differs greatly according to 
tbe nature of the soil, the climatic conditions} 
and the method of cultivation, and hence it would 
be misleading to give a detailed account of 
expenses and profit, especially as lucerne has 
not been hitherto grown to any appreciable extent 
in our soils. The results deduced from an ex- 
perimental crop of a few square yards could 
show nothing more than the adaptability of 
the pbnt to a particular locality. Lucerne as 
a food, whether it be for horses or cattle, for 
sheep or milch cows, stands pre-eminently the 
best among leaf crops. 
Sorghum vulgare, great millet, the Indian 
Jowari or Tamil Cholum, is one of the staple 
food crops in Upper India. The plant belongs 
to the grass family and yields a large quantity 
of nutritious edible grain. The poorer class 
of ryots in some districts in India live for 
months entirely on a diet of sorghum. We 
have, however, to consider sorghum here solely 
as a leaf crop, and as such it has been found. 
