212 CHEMICAL FERTILIZERS 



Calcareous Soils. Chalk soils or soils situated upon 

 limestone formations are well suited to the use of super- 

 phosphates, sulphate of ammonia and potash manure salts. 

 By long cultivation, the surface of these soils has often 

 been so completely denuded of its lime, that it may become 

 necessary to make applications of calcareous fertilizers. As 

 lime, chalk or ground limestone are easily obtainable in the 

 district, there is no great difficulty or expense attached to 

 this operation. Basic slag may also be used in these soils 

 when the surface lime has been washed awa)^. Somerville, 

 at Poverty Bottom, has obtained some striking results in the 

 use of basic slag on chalk soils. Nearly all of the artificial 

 fertilizers, as well as farmyard manure, do well on chalk 

 soils. Nitrification proceeds readily, and there is no fear of 

 acid conditions prevailing. 



Where the opposite condition of affairs prevails, and the 

 soil is particularly deficient in lime, the remedy is to apply 

 lime as a manure. A great deficiency of lime in a soil is 

 frequently recognizable by the presence of the weed spurry 

 on the lighter soils or sorrel on the heavier lands. 



Cold Climates. In most of the cold climates and the 

 more northerly part of the temperate zones, long winters 

 prevail, during which there is a cessation of agricultural 

 enterprise. Owing to the long periods of bad growing weather, 

 some stimulating manures are often required. When wheat 

 is grown, the land should be kept in a good condition and 

 well supplied with phosphates, whilst top dressings of sulphate 

 of ammonia may be used either during the winter or spring. 

 L,ime in some form or another is often very necessary, because 

 of the difficulties of nitrification. The speed of nitrification 

 in the soil depends, among other things, upon the temper- 

 ature and the prevalence of lime compounds. As the temper- 

 ature is low, it is necessary to see that the other accelerents 

 of nitrification are not deficient. Assisted by good soil 

 conditions Canada is able to push the wheat belt far up to 

 the north, whilst in the British Isles wheat growing becomes 

 of less and less importance as one proceeds in a northerly 

 direction. 



