290 



Journal of Af/riculturc, Victorid. [10 May, 1916. 



III. 



Average net profits per acre from Light and Heavy Dressings of Superphosphate 



over unmanured plots for the Season 1915— Longerenong, Rutherglen, 



and Werribee combined. 



Average net profils per acre from Light and Heavy Dressings of Superphosphate 

 over unmanured plots from all centres for Seasons 1913-14-15. 



No manure . . . . 13 * 2 . . I 



1 cwt. Super. .. .. 18-9 5-7 19 | 2 6 16 

 i cwt. Super. .. .. j 20-9 7-7 15 8 5 10 



2 cwt. Super. .. .. 21 '3 8-1 17 10 17 







These four tables show conclusively that dressings of 1 cwt. of super, 

 give a higher net return per acre after deducting the cost of manure 

 than light dressings of ^cwt. per acre; and this is not only true in good 

 seasons such as the one we have just experienced, but is also true of 

 normal and droughty years. 



Last year the half-hundredweight dressing gave an average net profit 

 over the unmanured plot of £1 4s. 8d. per acre. In the case of the 

 hundredweight dressing, however, the net profit per acre was £1 lis. 4d. 

 per acre after deducting the cost of the manure. 



For the past three years (which include the drought year) the 

 average net profit per acre from all centres was 20s. 8d. per acre from 

 the heavy dressing, as compared with 16s. 6d. per acre from the lighter 

 application. 



In these calculations the price of wheat was taken at 3s. 4d. per 

 bushel. At present prices the net profits would be correspondingly 

 great>er. Moreover in addition to the direct returns as measured by 

 grain yields, it must not be forgotten that the indirect returns from the 

 grazing of sheep would be much greater with the heavy dressings than 

 with the lighter dressings. 



2.— GREEN MANURE TESTS. 



One of the problems confroniTng every wheat-grower in the drier 

 districts is to extract from the soil the highest possible wheat yield, and at 

 the same time maintain unimpaired the productive power of the soil. In 

 the oldest wheat districts there is evidence that some of the practices in 

 vogue are slowly depleting the soil of its organic matter, which is the 

 basis of soil fertility and productiveness. 



Bare-fallowing is generally admitted to be the best preparation for 

 a wheat crop in the drier districts, but it has two manifest objections. 

 The land is lying idle for a whole year, bringing in no return; and, 

 moreover, the practice of bare-fallowing in our dry climate undoubtedly 

 leads to losses of organic matter. 



