Scientific Agriculture. 



526 



[December, 1911. 



cent. We should say that some nitrogen 

 was necessary, but not the full dressing ; 

 probably one-third of the lull dressing 

 would have been enough. Similarly plot 

 6 shows us the requirements in respect 

 of phosphoric acid. We see that with- 

 out phosphoric acid there is practically 

 no better result than with nothing at 

 all— there is a gain of only 10 per cent., 

 instead of 159 per cent. In such cases 

 we need have no hesitation in assuming 

 that all the phosphoric acid given on 

 plot 2 is necessary. Plot 7, without 

 potash, gives exactly the same result 

 as plot 2 with potash. Clearly from 

 such a result we may conclude that 

 potash manuring is unnecessary. 



Plot 8 is a duplicate unmanured plot. 

 If it gives practically the same result as 

 plot 3, we have coutidence that the ex- 

 pel iment has been properly carried out. 

 If, however,the results of these duplicate 

 plots do not agree within reasonable 

 limits we shall place less reliance on the 

 whole experiment. In such case the test 

 must be carried out with greater care 

 the next season. 



A field experiment laid out on a plan 

 such as this is a scientific experiment ; 

 and I think no one after following the 

 explanation of it will deny it the merit 

 of being practical. 



We are now in a position to consider 

 the question of the profitableness of 

 results such as those quoted from the 

 experimental fields. I have on several 

 occasions shown that not only are they 

 profitable, but that only with treatment 

 of this kind can real profits in most cases 

 be made- We will take the case of Mr. 

 Whelan's experimental potato crop in 

 1890. Most farmers in this country simply 

 make a living ; from a business point of 

 view they cannot be said to make a 

 profit. If they were to charge for their 

 labour at ordinary rates, and were to 

 reckon interest on the capital value of 

 their farms, it would be found that bal- 

 ance under present conditions was gener- 

 ally on the loss side. Thus, the net 

 outcome of 3^ tons of potatoes produced 

 on plot 3 of Mr. Whelan's experimental 

 field would be as follows : — 



Two ploughings and harrow- £. s. d. 



ings ... ... ... 1 4 



Seed ... ... ... 1 



Two hoeings ... ... 3 



Earthing up ... ... 2 6 



Harvesting ... ... 1 15 



Marketing ... ... 15 10 



Interest on capital ... 1 5 



Total cost £6 5 4 



Value of 3 J tons at 35s, per ton 5 10 10 

 Loss ... ... £0 14 8 



Now, compare this with the result 

 obtained on plot 4. This plot received a 

 dressing of 54 lbs. nitrogen per acre, 90 

 lbs. phosphoric acid, and 66 lbs. potash. 

 An examination of the results from the 

 different plots shows that all this was 

 not necessary. The full amount of phos- 

 phoric acid was required, but only half 

 the nitrogen and one-third the potash. 

 This mixture would at present be most 

 cheaply purchased in the following form:- 



£. s. d. 



144 lbs. sulphate of ammo- 

 nia at 12s. 6cf. per ewt ... 14 4 



193 lbs. concentrated super- 

 phosphate at 12s. 6d. per 

 cwt. ... ... 1 1 6 



37 lbs. potash chloride at 

 13s. 6d. per cwt. ... 4 6 



£2 4 



Freight and application 4 6 



£2 5 



The financial result then comes out as 

 follows : — 





£. s. 



d. 



Two ploughings and harrow 







ings ... 



1 4 







Seed ... 



1 







Two hoeings 



3 







Earthing up 



2 



6 



Harvesting 



2 







Marketing 



1 15 







Manuring 



2 5 







Interest on capital 



1 5 







Total cost 



£9 14 



6 



Value of 7 tons potatoes at 







35s. per ton 



12 5 







Profit 



£2 10 



6 



By adopting a suitable system of rota- 

 tion of crops, a still greater profit could 

 be obtained ; for there are certain crops, 

 namely peas, beans, clover, cow peas, 

 soy-beans, crimson clover, lupines and 

 other of the leguminosae, which have the 

 valuable quality of causing the soil to be 

 enriched in nitrogen from the air. By 

 introducing these crops into a rotation, 

 the cost of the nitrogen manuring, 

 amounting in the above case to 14s. 4d., 

 may be saved. By that means the profit 

 could be raised to £3 4s. lOd. per acre a 

 sufficiently handsome result, we imagine 

 to satisfy both the farmer and the finan- 

 cial institutions which have to aid him. 



The above result, however, does not 

 represent all the profit. There is still 

 more to come ; for it has been many 

 times demonstrated that the whole of 

 the manure is noc used up in the first 

 season of application. Under the most 

 favourable conditions only about two- 



