ANTAGONISM BETWEEN ALKALI SALTS 115 



containing 50,000 parts per million of magnesium sulphate 

 were made to produce much better growth by adding 

 lime than without it. Most alkali soils contain consider- 

 able lime. This may account for the large quantities of 

 alkali sometimes present without serious injury to crops 

 growing upon them. 



The work of Lipman and Gericke (n) indicates that 

 even in a clay soil of the arid region there was antagonism 



L|i^gj^^,%^*BW'->^^ 



Fig. 16. Black Alkali Crust Forming where the Land 



has been Wet. 



between sodium chloride and sodium sulphate, and be- 

 tween sodium chloride and sodium carbonate in the second 

 crop of barley, although none was shown in the first. 

 That the time of contact might have had some effect is 

 shown from the observation that neither sodium chloride 

 nor sodium sulphate was stimulating in concentration of 

 1000 parts per million for the first crop but were toxic 

 for the second. Calcium sulphate was antagonistic even 

 in comparatively small quantities when added to a soil 

 containing 4000 parts per million of sodium sulphate. 



Lipman and Sharp (14), in an experiment with a natural 

 soil containing 6400 parts per million of total salts com- 



