LIMITS OF ENDURANCE OF DIFFERENT FARM CROPS. 397 



as the check-pot. In pot 13'8, however, the growth was 

 strongly affected. In pot 139 the plants were nearly dead, 

 and in No. 140 they were quite dead. 



These experiments showed that germination of rye is 

 already affected by the presence in the soil of *1 per cent. 

 NaOl, it was not however, prevented by amounts up to *25 

 per cent. The subsequent growth of rye is affected by '05 

 per cent., but under favourable conditions the plants may 

 recover in the presence of sodium chloride up to '1 per cent. 

 With '15 per cent, the subsequent growth is strongly affected 

 and with '20 per cent, the plants die. 



In order to ascertain the amount necessary to prevent 

 germination, a farther series of four pots were sown on 

 October 10th, 1903, with the following proportions of com- 

 mon salt : — 



No. 141, *30 per cent. NaOl 

 ,, 142, oo ,, ,, 



„ 143, '40 

 „ 144, '50 



It was found on examining these pots on October 21st, 

 that the germination in Nos. 141 and 142 had been strongly 

 affected, and that in No. 143 the plants had hardly germin- 

 ated at all, the germination being still more feeble in No. 144. 



By December 4th, the plants in all pots were dead. 

 Germination of rye is therefore prevented by '4 per cent. 

 NaOl and over. 



Experiments tvitli NcioCO s . 

 On 6th August, 1903, six pots were filled with the soil, 

 10 grms superphosphate to each pot, and the following 

 quantities of sodium carbonate, and 13 grains of rye : — 



No. 145, '1 per cent. 

 » 146, *2 „ 

 „ 147, *25 „ 

 „ 1^8, -30 „ 

 » 149, '85 „ 

 „ 150, '40 „ 



