182 QUEENSLAND AGRICULTURAL JOURNAL. [1 Ava., 1899. 
Mr. A. Wart, of the Agricultural College, Gatton, then read the following 
on— 
SUB-DRAINAGE. 
Having, read two papers on the importance of sub-draining on two previous 
occasions—the last being at the Conference held two years ago at the Queensland 
Agricultural College—and finding a journal containing the reading in the College 
library, it struck me as being unnecessary to repeat it. I have it here, and should 
delegates wish to have it read I shall do so. I£ not, I will pass on to a little practical 
experience I have had since then in reclaiming a swamp. A year and ten months ago 
I was sent to Dunwich to examine and report on the possibility of draining a swamp 
of some 80 or more acres. 1! found it a vast aeeamiteten of vegetable and peaty 
matter, that had been growing and decaying for ages, and growing a variety of aquatic 
plants. I tested for bottom in various places, and found that the mass rested on san 
similar to the sand on the beach; which satisfied me that the sea had at. one time 
ebbed and flowed over it, and that the sand, or old sea-bed, should be my guide for 
bottom. Ireported favourably, and was asked to carry out the scheme in accordance 
with my report. In sub-draining, you must have a firm bed for the pipes, otherwise 
they will get pressed out of position and choke the drain. A considers he portion of 
the swamp lay low and level. In the low parts I could bottom on the sand in 3 feet; 
in other parts I had to go down 5 and 6 feet to reach the sand; but it had to be done, 
as there was nothing firm enough between the surface and the sand on which to bed 
the i es; and even on the marti we met with short stretches of quicksand, which gaye 
trouble, and would require timber to carry the pipes. In draining, the first thing to 
be done is to find the lowest ground, and Eenten that open your main leader. 
The laterals, or minor drains, are then marked off, when you have decided upon their 
width apart. Should the land all slope one way, one leader will be sufficient, if the 
Tength of the laterals is not too great—say, over 200 yards; in such case, a sub- 
leader in .an oblique direction should be put in across them. In this instance 
I required two main leaders on to the beach, and sub-leaders off these according to 
the ity of the ground. I should mention that, in draining such land as I have 
described, it is not advisable to lay the pipes and fill in at once, as all spongy or peaty 
soils shrink and subside when drained, and it may happen that the drains will require 
deepening. In this instance the subsidence was from 6 inches in the shallow to 14 
inches in the deeper drains in a few months. Land that would not carry a ca 
became sound enough to carry horses. Another important reason why such drains 
should not be filled at once: the land is sour, and the more it is exposed to the action 
of the atmosphere the sooner it will sweeten. Jt can hardly be expected that such 
land would become immediately productive, it being heavily charged with ulmic acid. 
To cure that, an application of caustic lime is necessary; it acts directly upon 
vegetable matter after draining (lime is simply wasted on undrained land). “Had I 
been left to finish the draining, and prepare the land for cultivation, £ would have 
applied from 75 to 150 bushels lime per acre—say, 23 to 5 tons, at 30 bushels to the 
ton. From 75 to 240 bushels may be considered average quantities from the lightest 
to the heaviest soils. Lime has been applied to the land in the old countries for & 
very long period of years; the object has always been the same—to increase the ctops 
by stimulating the soil. If ploughed in, it has no immediate effect, but if simply 
harrowed or scarified in, it has effect at once. ‘Oyster middens” are found at 
intervals along the shores of the island containing large quantities of decompos 
shells, which—in the event of lime being too costly—could be applied with good effect 
(not to be compared to lime, of course) as they would combine with the light peaty soil 
and fix it. After dealing with the most difficult portion of the swamp, I left for 
Emerald Downs and the work stopped, to the great disappointment of the Medical 
Superintendent, who took a keen interest in it. 
Mr. Warr also concluded his paper by endorsing the remarks of Mr. 
Gibson relative to the necessity for legislation to deal with individuals who 
refused to allow drains to pass through their properties. 
Mr. J. Parke (Tinana): Some land that I had been cultivating for a 
number of years was of a red volcanic nature—originally forest land, but it 
used to give me considerable trouble at times. About Christmas, or before, @ 
very heavy thunderstorm would come down. At this time my crop of corn oF 
potatoes would be looking splendid, but when the hot sun came out after the 
rain the whole crop would be spoiled within the course of a couple of days. I 
started then to open some drains, much against the advice of my neighbours, 1 
may add, and at first I used stones for the drains, for on the other side of the 
