198 
THE TROPICAL 
AGRICULTURIST. 
[Sept. 1, 1900, 
or near the surface, when the percolation of rain- 
water through the soil is exceeded by evaporation 
at the surface. Under such conditions the soluble 
parts of the soil unused by plants, such aa the 
sulphates of soda and magnesia and common salt, 
may accumulate to such an extent as to form ft 
white incrustation on the surface that renders the 
land wholly or partially sterile ; this occurs, for 
instance, in the white alkali soils of America, and 
again in other hot countries where irrigation is care- 
lessly practised without under-drainage. The pheno- 
menon on a small scale is not unknown to gardeners. 
Plants kept in pots for some time without a change 
of soil, and watered regularly with spring or well- 
water, gather up a hurtful excess of saline matter; 
and we have seen on a greenhouse Rose-border a 
characteristic saline efflorescence due to " white 
alkali " from the water used. The remedy is in all 
cases the same — to wash the salts out of the soil 
into the subsoil by increasing the amount of per- 
colation through the soil. Professor Warington 
might have found an interesting illustration of the 
point in Sir Alfred Milner's book on Egypt, where 
he shows how the English irrigation engineers found 
many of the lands had been rendered sterile, because 
only the old irrigation canals bringing the Nile water 
to the fields were in use, while the canals at a lower 
level, which should have returned to the Nile the 
water that had percolated through the soil, had been 
allowed to decay. When, however, the drainage canals 
were restored, and the lauds well drowned to wash 
out the saline matter that had accumulated by 
evaporation, the fertility returned. 
In conclusion, we have to thank Professor Waring- 
ton for a very instructive book on a little-known 
subject, that cannot but be fruitful both of thought 
and of suggestion to the agricultural teachers to 
whom it is commended, and also to the gardener 
and farmer. We cannot, however, help wishing that 
the book were something else — it is after all a com- 
pilation that might have been drawn up by another 
man. What the younger generation of agricultural 
investigators and teachers would have accepted from 
the Sibthorpian Professor with even fuller gratitude, 
woald have been a liltle more criticism and suggestion 
of fruitful lines of research. The energy of the 
American researchers in accumulating results is not 
always tempered by wisdom, sometimes the vpood 
cannot be seen for the trees, and instead of a 
wholesale commendation of their work, we should 
have preferred^an ampler measure of the judgment 
. and long experience of Professor Warington himself. 
D. H. — The Gardeners' Clironiele. 
MANURES: 
Being a Lecture delivered by Mr. A. P. Sanson, 
(Agricultural Teacher, Jamaica.) 
If there be a subject the study of which the Agri- 
culturist can neglect without doing material harm 
to himself, it is not the study of manures. In an 
island like ours whose wealth is only in the soil, and 
whose population is rapidly increasing, the prudent 
man looks forward to the time when there will be 
little or no maiden land to be cultivated, and the success 
of the Agriculturist will depend entirely upon his 
skill to accumulate and apply manure. Even now 
our small land owners are crying out. After one 
or two years' cultivation of a plot of ground they 
abandon this latter, which with careful tillage and 
the application of manure, would yield far more than 
the badly tilled, so called " strong land," and save 
the planter the money paid as rent. Only to say 
this, however, will not bring about the desired effect 
upon our people. They want to know bow to come 
in possession of manure, but this is not far to seek. 
Tlie scientist if asked, will tell us of special manures 
such aa sulphate of ammonia, nitrate of soda, &o., 
but tboy are far beyond the reach of the ordinary 
planter, nor does he need be anxious about them, 
for he has always immediately around him many 
things that can be turned to valuable fertilizers if 
only properly treated. Lat us look for example, at 
nature's method, which is always exemplar}'. Here 
is a luxurious grovifth of trees and shrubs. Unlike 
our cultivated plant, these remam on the same plot 
of ground for years in succession, and, instead of 
diminishing, accxuice increased vigour and luxuriance 
every season. They never cry out as our cultivated 
plants seem to do that the soil is poor. The reason 
for this can be easily explained. Instead of beiug 
removed to some remote place, the leaves, flowers 
fruits, &c., of the plants of natural growth fall back 
upon the soil, decay, and return to it the elements 
of which it was robbed. In this way the fertility 
of the soil is constantly kept up. O:: the contrary, 
when we cultivate our plants we reap hoc only the 
crops, but the leaves, stems, and sometimes even 
the roots of the cultivated plants, in this way the 
soil is year after year robbed of I:s fertilizing elements 
and in course of time must become impoverished! 
The planter should remove from the fiel l nothing 
but what he requires for home consumption or the 
market. He should plough into the soil all the leaves 
stems, and roots of the plants cultivated, and of the 
weeds that grow- Besides these latter if permitted 
to remain will deprive the cultivated plants of their 
food. If seeds are permitted to seed in the field 
this will cause increased labour. If these points are 
carefully attended to, such a course of procedure 
will give longevity to the producing power of the 
soil. In addition to these, we have numerous other 
substances that can be most effectively employed 
as manures. Every planter should always be making 
a compost heap upon and into v/hich he should cast 
sweepings from the house, the kitchen, and the yard • 
also hair, blood and bones of the animals that 
might be killed, rags, the litter from the stable, the 
goat-pen, the stye, the rabbit-pen, the fowl-house 
night soil, dead fowls, and all things that will decay! 
It is by dint of such carefulness that we can always 
be in possession of manure to a greater or less 
degree, manure cheaply got, but of great value. 
Another instance that comes wilhiu the reach of 
every one, and which claims special attention as a 
fertilizer is wood ash. Ashes may be collected in 
large quantities in every home. It contains potash 
which is required by every plant, and enjoyed by 
all as a luxury. Therefore, waste not the ashea. 
but give it to the plants. The common salt also 
is a valuable fertilizer. But it may be said that they 
cannot afford to use this as a fertilizer. The elements 
in it which makes it valuable as such are soda and 
chlorine. Well, both these are to be found in the 
ashes above spoken of. It will do well, however, to 
pour sea water into the holes dug for the purpose 
before planting the coconut or sugar cane. In res- 
pect to the application of manure to the soit it must 
be understood that the parts of the manure used 
up by the plants must assume a liquid form. The 
plants cannot take solid bits of food as we do and 
water is a great influence in dissolving the plant 
food. When we put sugar in a glass and pour water 
upon it the sugar seemingly disappears, and the 
only evidence of its presence are the colour and 
taste of the water. When we drink this coloured 
water we drink in the sugar too. This is similar 
to what goes on among plants. Water is necessary 
to enable them to take up and assimilate food. I 
scarce need state also that the plants send out 
their roots in search of food below the surface of 
the ground, and that before the water can penetrate 
the earth to bring about the desired result the soil 
must be properly tilled. Tilled as a rule to the 
depth of about eighteen inches, unless the soil before 
reaching that depth be of such a nature that it 
will yield no support to the plants. When this 
ploughing has been accomplished lay over the soil 
the manure collected, and bestow a kind of secondary 
tillage Eo as to ensure the manure getting mixed 
with the soil. When there are plants such aa 
bananas, already in the field, the manure need not 
