Oct. 4, 19IS 



Effect of Alkali Salts in Soils on Crops 



Table IV. — Effect of soil moisture on the toxicity of sodium carbonate on wheat plants 



NUMBER OK S^EDS GERMINATED IN EACH GLASS 



AVERAGE HEIGHT OF PLANTS (CENTIMETERS) . 



4,000. 

 5,000. 

 6,000. 

 7,000. 



8,000. 



9,000. 

 10,000. 

 11,000. 



DRY MATTER PRODUCED PER GLASS (gRAMS) 



4,000 

 5,000 

 6,000 

 7,000 



8,000 

 9,000 

 10,000 

 11,000 



o. 196 



. 202 

 ■154 

 .078 



.025 



From Table IV it is seen that the number of seeds germinating, the 

 average height of plants, and the dry matter produced all decrease with 

 the increased concentration of the alkali. The plants appear able to 

 endure alkali better with a fair supply of moisture in the soil than where 

 the soil is dry. This may be due to the fact that the soil solution is 

 diluted by the water. Where the soil moisture was as low as 12.5 per 

 cent, growth practically ceased at 7,000 p. p. m. of sodium carbonate, 

 but in the wetter soils there was growth with as high a concentration as 

 11,000 p. p. m. 



