LIMITS OF ENDURANCE OF DIFFERENT FARM CROPS. 393 



In order to determine within narrower limits the point at 

 which the growth commenced to show signs of being 

 influenced by the presence of carbonate of soda, 3 additional 

 pots were sown on July 30th, 1903, containing respectively: 

 No. 104 *1 per cent, sodium carbonate. 

 „ 105 '15 „ 

 „ 106 '2 



On August 21st, 1903, when these pots were examined, 

 the germination was unaffected in all three. In pot 104 the 

 growth was quite vigorous and unaffected ; in No. 105 the 

 growth was slightly affected, and in No. 106 somewhat 

 more so. 



From the above it is concluded that germination of barley 

 is not affected by quantities of carbonate of soda up to '25 

 or *30, and is absolutely prevented by '60 per cent, car- 

 bonate of soda in the soil. The subsequent growth of the 

 plant is not affected by quantities below '15 per cent., at 

 which point the effects of carbonate of soda are distinctly 

 noticeable. *4 per cent, and over prevent the growth of 

 barley. 



Experiments ivith ammonium sulphocyanide. 



Six pots were filled and sown on December 3rd, 1902, as 



in the preceding experiments, the following quantities of 



ammonium sulphocyanide having been added previous to 



sowing : — 



No. 107, '001 per cent. NELCNS. 



108, -002 



109, '003 „ 



110, *004 



111, -005 



112, -006 



In all these cases the germination was unaffected and 

 the plants were growing vigorously on December 13th in 

 all pots except Nos. Ill and 112, in which the growth was 

 affected. 



