10 April, 1918.1 



Wheat Man II rial Trials. 



223 



value of the increase produced b}^ the manure, and consequently it will pay 

 when the price of wheat is high to give a somewhat heavier dressing 

 than when the price is low. Reference to any of the attached tables, on 

 which the net profit is calculated on the basis of wheat at 4s. a bushel, 

 will demonstrate that if wheat had been calculated as worth 4s. 9d. a 

 bushel still heavier dressings than those indicated would have been pro- 

 fitable. Conversely, if wheat fell to 3s. ,2d., somewhat lighter dressings 

 would have been the most profitable. A perusal of the tables for the yields 

 will show that it is well within the capacity of moderate dressings of 

 superphosphates on many wheat soils to double the yields^ or at any 

 i-ate to produce net profits in the vicinity of £1 per acre over and above 

 the cost of the manure. Hence the importance of accurate manurial de- 

 terminations is strikingly demonstrated. 



Owing to the seasonal fluctuations, fairly wide differences in the 

 results are obtained, but when the results of a number of years are con- 



Half -acre Manurial Plots at the Research Farm, Werribee. 



sidered such differences tend to be eliminated, and the figures so obtained 

 furnish a more reliable basis for use in practice. Such determinations 

 Avould jirobably be made on many farms if there were ready facilities 

 for insuring accuracy of results ; further, the expense of conducting the 

 trials has to be considered. At each of the State farms, however, por- 

 tion of the area is devoted to annual manurial trials of a permanent 

 character. The crop is sown on fallow ground and is located on the iden- 

 tical spot each year, so that the cumulative effect of the manures applied 

 is determined in each case. Full precautions are taken to insure accuracy 

 of the results, and the produce is weighed. Besides superphosphate, a 

 number of other manures and combinations of manures are tested side 

 by side in plots. Each plot is half an acre in area, and the whole field 

 is treated as far as possible just as it would be on a farm. Federation 

 wheat is the variety sown. 



