270 POWER OF SOIL TO ABSORB SALTS [chap. viii. 



The experiments recorded above and the results 

 of the examination of drainage waters go to show 

 that nitrate of soda should only be employed when 

 there is a crop in possession of the ground and ready 

 to seize upon the salt as soon as it becomes diffused 

 through the soil. Only on dry soils can it be safely 

 applied as early as the sowing of the seed ; in wet 

 climates sulphate of ammonia will often be preferable 

 if the soil is warm enough to induce reasonably quick 

 nitrification, and when large quantities of nitrate are 

 wanted they should be put on by successive applications 

 of not more than i cwt. per acre at a time. 







