JANUARY 1e- 1906. 
THE AUSTRALIAN GARDENER. 
te Seema a 
| wericulture and Stock. 
Irrigation on the Farm. 
By. A. S. Kenyon, C.E. 
RRIGATION may mean either supplementing a 
rainfall Seticiont for the whole year, or simply 
giving the plants water during dry periods 
within the year, In the first case, the water 
used must, of course, be caught off land which is 
not cultivated, while in the latter the land 
actually being irrigated may yield from the 
excess rains of the wetter months sufficient water 
totide over the trying intervals in the drier 
part of the year. It may be employed either 
for increasing the returns obtainable under 
ordinary conditions or for obtaining yields not 
otherwise possible. It must be born in mind 
that the heavier the crop the greater the volume 
of water required, as the leafsurface or evapora- 
ting area is roughly in proportion to the yield. 
A fairly heavy crop of hay or grain will require 
for transpiration through its leat surfaces the 
equivalent in water of 12 inches in depth. 
Transpiration is continually going on; but is, 
of course, greater in the drier months. Hence 
the moisture of the wet months must be stored 
forthe requirements of the drier. Hallowing, 
with subsoil stirring, and frequent harrowing of 
the surface, will conserve and carry forward 
much water from one season to the next; but 
these methods cannot obviously be applied to 
perennial crops. These crops must in almost 
all parts of the State receive a greater or less 
yolume of added water to insure profitable 
returns. The volume of water to be added 
cannot be stated exactly; local conditions so, 
influence requirements, and are so variable, that 
only indications can be given the grower. whe 
must ascertain for himself the correct quantities 
As instance of the extreme variation in this 
respect, the Mildura fruit-grower gives his trees 
24 to 30 inches during the year, while, for 
similiar trees at Doncaster, not more than 2 
inches are added in ordinary seasans, and 
nothing in exceptional ones, Near Bendigo, 7 
inches has been found sufficient in a dry season 
to produce heavy summer fodder crops, while 
in the southorn districts a somewhat Jess depth 
is sufficient for similiar purposes, For perennial. 
fodder crops, such as lucerne, an almost unlimi- 
ted ‘amount of water may be given, 36 inches 
for the year not being excessive. Cereal crops 
though grown in the moisture months, require, 
from the practical difficulties in the way of 
economical distribution, from 6 to 12 inches, or 
eyen more. } 
Appiied to oereals irrigation on the small scale 
will rarely repay the farmer: the profit.on these 
crops being small and the necossary areas large 
The right kind of crops for irrigation are fodder 
—for dairying purposes are generally to make 
ensilage, and fruit trees—especially when near 
large towns which afford a ready market for 
fresh fruit. In the more ,arid of the northern 
and north-western districts, and especiully in the 
Mallee, the value of a small quantity of irri- 
gated green feed forthe working stock is very 
eat from a medicinal point of view, while the 
health of the farmer himself and his family is 
greatly improved if fresh vegetables are obtain- 
able on the farm. It is nota matter of much 
difficulty for the farmer to irrigate close upon 
one acre of green feed—maize, amber cano, 
lucerne,&c.—and vegetables; all that is required 
is an extra thousand cubic yards capacity in his 
tank. This cin easily be filled if channels are 
near, or from most catchments if properly 
improved. 
With irrigation, as for all good cultivation, 
drainage is assential. In many of our northern 
soils, the natural drainage is sufficient; but in 
some cases,and in most of the southern soils, 
artificial drainage must be resorted to in order 
to secure the best results, This may be effected 
in any of the ordinary ways For orchards 
the agricultural drain-pipe system is about the 
best. Careful attention must be paid to the 
soil and especially the subsoil. when fixing the 
depth and distance apart ofthe drains. Drain- 
age of land is a big subject involving many con- 
siderations, and needs dealing with in a separate 
article. Stirring the surface of the soil as soon 
as possible after a watering is also assential. to 
prevent evaporation and conserve the moisture 
Irrigation and continual cultivation are insepar- 
able to insure success. 
Australian conditions differing so greatly 
from those of ths old world, whence came our 
first farmers, have compelled the adoption of 
aguicultural appliances and methods peculiar to 
the southern continent. The stripper, harvester 
stump-jump plough, and other implements can 
be cited in support of the statement as to 
appliances, while a notable instance of localised 
methods occurs at Doncaster, the well-known 
fruit growing district. Here, a system of partial 
irrigation by small dams of limited catchment 
has converted a somewhat precarious industry 
into one of large profits. That peculiar local 
conditions—conditions rarely occuring in the 
State—contribute to this [result may be granted: 
these will be referred to later. Doncaster, and 
its surrounding district, is undulating and, con- 
sidering its proximity to the sea, isat a com- 
paratively fhigh elevation. The rainfall, es- 
pecially in the dry months, is, however, subject 
to great fluctuations, and it is in these months 
—when evaporation is at its highest—that the 
plants require the greatest quantity of moisture. 
As the subsoil is apparently unsuited for storing 
sufficient of the surplus from the wet or cereal- 
growing months, the fruit-growers have recourse 
to stored water at times of drought. The stored 
water in most cases cemes off the orchard itself, 
and is returned to the soil as needed, gener- 
ally between the end of November and the end 
of March—in nct greater volume than 2 inches 
in depth per acre. 
The practise of irrigation at Doncaster is not 
_ confined to a few enthusiasts. Almost the whole 
of the land is under horticulture, aad the dis- 
trict is dotted with dams, The orders generally 
are small, and of course many of them are with- 
out gullies. Consequently catchments are 
limited, and of poor quality, while economical 
sites for storage are rare. Restricted as the 
catchments are, they are all cultivated—land 
being too valuable to be allowed to lie idlo—and 
their run off is, in consequence, small. In some 
cases a few chains of road running alongside 
the orchard is all that is available, yet with the 
small volumes used and the economical methods 
of distribution employed, they suffice. 
The type of storage generally may be termed 
a hillslde dam. The storage is partly in excava- 
tion and partly in fill, the material excavated is 
used as embankment to retain water above the 
surface. Owing to the lack of gullies, the ends 
of the bank have to be returned to the upper 
ground to retain the water in store. The bank, 
rarely more than 8 ft in height, and retaining 
sbout 6 ft of water above the surface of the 
ground, departs from the usual type in many 
respects, notably slopes and manner of construc- 
tion. The inner or water slope is generally as 
steep as 14 to 1, that is, one and a half feet 
diminution in horizontal width for each in- 
crease of one foot in height, while the outside 
slope is sometimes steeper, approximately one to 
one. Crest widths are generally small, 3 to 4 
ft being therule. ‘The slopes mentioned, particu- 
larly the water one, would be unsafe in most 
soils, especially those of a clayey nature, but 
here, as the dams themselves witness, the mate- 
rial permits the employment of such extreme. 
batters. The explanation is that, by the method. 
adopted for bnilding, the inner face is composed, 
of stuff taken from the deepest part of the ox- 
cavation, which is largely rock, only slightly 
dec »mposed and fu'l of quartz fragments. Where. 
such is not the case the slopes have to be much 
flatter, or otherwise there is constant trouble 
and expense in repairs, not to mention the loss 
of valuable water. In con-truction the seats of 
the banks are ploughed and the surface soil 
removed. The surface soil of the excavated 
portion is placed at the outer toe of the 
bank, the stuff beneath is then excavated and 
built in steep sloping layers. The last layers, 
which form the whole of the water face are, as 
already explained, taken from the bottom, and 
become practically a slant puddle wall, not only 
to the bank, but to the slope of the excavation 
as well. This method of building is highly suit- 
able to the local conditions, the rock into which 
the dams must for the most part be sunk being, 
as said before, very open, requires facing or 
puddling, to make it watertight, The rock itself 
is really more dangerous to the efficiency of the 
storage than the banks Outlets are composed 
simply of pipes, wrought-iron galvanised, of 
from 2 to 3 inches diameter, placed in trenches 
cut down to the lowest level of the excavation 
and refilled with clay. 
Healthy Horses. 
By S. S. Cameron, M.R.C.V,S. 
ALTHOUGH, by constant association with them, 
most horsemen acquire an instinctive compre- 
hension of the normal and healthy features of 
their charges, it may be well to set down in 
definite terms what are the signs and habits of 
health in horses before dealing with the condi- 
tions which may induce an abnormal change, or 
with the methods and practices in management 
which make for the prevention of such a 
change. : : 
SIGNS AND HABITS OF HEALTH 
IN HORSES, 
_ Attitude—Stands with feet flat on ground, 
limbs placed evenly side by side, with equal 
bearing and weight on each. The horse occa- 
sionally stands at ease by resting the hind limba 
alternately—the joints are partly flexed, the fet- 
lock is _knuckled, the heel raised, and the toe 
rests lightly on the ground. The fore limbs are 
never so rested in health. 
Fests at night and during the day, whén un- 
disturbed, by lying down with the knees and 
hocks flexed, and the body inclining slightly to 
one side. : 
Rises by raising the forequarters first, thon 
gathers the hind limbs under the body, and 
springs to the upright position. gi 
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