GENERAL CONDITIONS IN NEW ZEALAND 35 



This table clearly shows that the soils of the wheat 

 producing areas of New Zealand contain the ingredients 

 necessary for the economical and efficient growth of 

 wheat to a remarkable degree. Few other countries 

 can compare with New Zealand in this respect. Russian 

 soil is perhaps richer, while the United States of America 

 wheat belt possesses many similar qualities. European 

 areas do not surpass the Dominion in natural fertility, 

 while Australia and Argentina are on the whole out- 

 classed by her. 



Thus the conclusion is forced upon us that New 

 Zealand possesses a differential advantage from the fine 

 qualities and equal distribution of her soil ingredients. 

 After considering the advisability of making a systematic 

 soil survey of the soils of the Dominion, we shall turn 

 our attention to an investigation into the possibilities 

 of improving the natural fertility of the soil by the use 

 of fertilisers, both direct and indirect. 



(b) A Soil Survey. In every country water supply 

 is the most important factor governing the productivity 

 of the soil. Given a sufficiency of water, the chemical 

 constitution of a soil is usually of secondary importance. 

 The textural classification of soils into sands, loams, 

 clays, etc., is essential in defining their cultural character, 

 and, if this classification is accompanied by the water 

 requirements of the soil, we gain some idea of the agri- 

 cultural value of the land. 



The factors controlling productivity are of two groups 

 water supply, and chemical constitution of the soil 

 and if it is necessary to assess the agricultural value of 

 the land, we must classify the soils according as they 

 conform to or differ from types, and group the types 

 according to their water requirements. This latter 

 requirement is necessary because of the fact that in any 

 locality with land of a uniform chemical composition 

 and with a uniform rainfall, the supply of water may 

 be excessive in one part and defective in another. The 



