1 Mar., 1899.] QUEENSLAND AGRICULTURAL JOURNAL. 167 
4, A field of potatoes yielded per acre :— 
Tons cwt. qr. Ih. 
Manured con ux a om nee «- 9 18 0 24 potatoes. 
Unmanured ... Ae a3 fz 0) SRT AL OV OF 6 Ey 
Increase ... — oxx) at a Pe AA Sa? S18 
” 
The next question the farmer naturally will ask is: “ What about the cost 
of these fertilisers ?’? In reply to this we have the cost of the manuring, the 
yalue of the resulting increase, and the profit per acre in each of the above 
cases. 
The following table sets forth (A) the cost of the manuring; (B) the value 
of the resulting increase; and (c) the profit per acre in each of the above 
cages :— 
A. B O: 
&os. d. eo & Gh £& s. d. 
Experiment 1 » Bil 2B 48" 9 iy 
” Bags Bl Ys 5 6 O 2 14 10 
” BT nc FL mW 4h a O I By 
” Cr, Me S10 © .. Oils © 
It will be observed that even such a simple experiment, in which the value 
of a complete manuring with nitrogen, phosphoric acid, and potash is compared 
with the absence of manure, effects a highly valuable revelation. In 
experiments 2 and 4 of the above examples the profits realised were exceptionally 
high, amounting to £2 14s. 10d. and £6 14s. 8d. per acre respectively; in 
experiment 1 the result was also satisfactory, £1 17s. 7d. per acre; whilst in 
experiment 3 the profit was only 1s. 2d. per acre, which shows clearly that the 
manuring had been too liberal for the land experimented on, and, therefore,. 
the good effected was neutralised, as regards profit, by the unnecessarily large 
outlay for the manure. ‘This may be distinctly seen by comparing experiments 
2, and 3, which were made with the same crop and the same manuring. 
Tf the Queensland prices are taken, it will be seen that the resulting profit 
per acre would be much larger. For instance, take experiment 4. There the 
increased yield amounts to very nearly 5 tons per acre. On the unmanured 
lot this would represent the whole crop, and would at present prices be worth 
about £40. On the dressed plot the yield is nearly double or about £80, 
whilst the actual cost of the manuring only amounted to £1 14s. 4d. per acre, 
the fertiliser being applied in the following proportions :— 
On a Plot of 121 7 ee, 
Square Yards. PAN. 
owt 
Nitrate of soda ... cor an 2 w Gl 
Thomas’ phosphate powder... 12 -° «. 42 
Sulphate of potash... ary 4 ois 
At the prices per ewt. given in the February number of the Journal in 
reply to a correspondent (in which by the way an error crept in giving the price 
per sack, instead of the price per cwt., corrected in this issue), the cost of the 
mixture per acre would be £1 14s. 73d. : 
Of course it may happen that the soil in question is not deficient in one of 
the ingredients or perhaps in two. In such a case a portion of the land should 
be divided into several plots. It may be thought that plots as extensive as + 
or at least $ of an acre offer the best guarantee for trustworthy results. But 
this is not the case. It is difficult to find 3 or 6 acres in a field, capable of 
being divided into 8 plots, which would be so similar to each other in condition 
that any variation in harvest obtained from them could unhesitatingly be 
attributed to the action of the various manures employed. 
