FERTILIZERS AND PLANT PRODUCTS 177 



supply of fertilizer supplied. In wet climates, like Ireland, 

 unsatisfactory soils and insufficient manure may produce 

 partially successful results, which could not possibly be 

 imitated in a drier and colder climate. Accumulations of 

 either acidity or alkalinity are harmful. Acidity is more 

 frequently produced by excessive quantities of organic 

 matter than by any accumulation of mineral acid, although 

 the use of sulphate of ammonia in large excess may pro- 

 duce the latter result. Alkalinity is produced by the appli- 

 cation of lime or by the residues of soda left from excessive 

 applications of nitrate of soda or by natural decomposition 

 of soda felspar in the soil. The removal of acidity is 

 generally obtained by the use of lime, while the removal of 

 alkalinity can be accomplished by the use of super-phos- 

 phates and gypsum. In the former case the neutralization 

 of the acid is due to the calcium bi-carbonate formed from 

 lime, carbon dioxide, and water. In the latter case sodium 

 carbonate, sodium humate, or soluble sodium silicate is 

 decomposed by calcium sulphate with the formation of 

 neutral sodium sulphate and other harmless substances. 

 Cultivation is one of the best means by which most is made of 

 the fertilizing ingredients in the soil, or supplied in the form 

 of fertilizers. Without efficient cultivation, full utilization 

 of the fertilizers will always be impossible. 



REFERENCE TO SECTION VI 



" Compound Manures," Journ. Board of Agriculture, 191516, p. 675. 



Clouston, "Artificial Fertilizers for Cotton," Agric Journ. India, 1908, 

 p. 246. 



Bald, "Experiments in Manuring on a Tea Estate," Agric. Journ. 

 India, 1913, p. 157; 1914, p. 182 



D. 12 



