76 



Fluoncles on Wheat, 1922. 



IV. The Influence of Silicates on Wheat, 1922 (3rd Year). 



The experiments of 1920 and 1921 were carried a further stag^e, 

 no further additions being g-iven, but wheat being sown again in 

 the pots on December 21st, 1921. The previous years had shown 

 calcium silicate to give an increase in the crop as the amount of it 

 was increased, and this up to an application of 4 tons per acre, the 

 increase being more marked the second than the first year. On 

 the other hand, kaolin produced no effect, and magnesium silicate 

 a less marked one than calcium silicate. 



The 1922 results were of similar nature, showing a continued 

 benefit from calcium silicate, increasing as more was used, while 

 that of magnesium silicate was, on the whole, less. 



The three years' results follow : — 



From this it would appear to be clearly established that calcium 

 silicate is a far from inactive form of lime, and that this may have 

 a bearing upon the experiments recorded under II. in this section, 

 as regards the relative efficiency of lime and chalk. 



