476 Transactions. 



Art. XLI. — On the Proposal for a Soil Survey of New Zealand. 



By Leonard J. Wild, M.A., B.Sc, F.G.S., Lecturer in Chemistry, Canter- 

 bury Agricultural College. 



[Bead before the Canterbury Philosophical Institute^ 6th December, 1916 ; received 

 by Editors, 30th December, 1916 ; issued separately, 7th December, 1917.] 



Contents. 



I. General Methods of Soil Survey — 



1. Factors of which a Soil Survey must take Account. 



2. Tulaikoff's Classification of Soil-survey Methods. 



3. {a.) Genetic Classification criticized. 



(b.) Geologico-petrographical Classification criticized. 



(i.) Rigg's Paper on the Soils of the Biggleswade District, 

 (ii.) Foreman's Paper on the Soils of Cambridgeshire, 

 (c.) Combined Classification. 

 II. Method of Soil Survey for New Zealand — 



1. Definitions of Terms proposed. 



2. Subdivision on Basis of Soil- utilization. 



3. Nomenclature. 



Til. Application of Principles — 



1. Soil Districts of the South Island. 



2. Scheme for Description of Soil Formations. 



I. General Methods of Soil Survey. 



In considering the relative advantages of the various methods of soil survey 

 that have been proposed it is reasonable to demand that a method shall take 

 into account to the greatest degree possible all those features that most pro- 

 foundly affect the agricultural potentialities of the soil. These are (1) local 

 climate ; (2) soil texture ; (3) composition ; (4) nature of subsoil. It is 

 difficult to arrange these in order of relative importance, but it can be 

 shown that, except in abnormal cases, chemical composition is of least con- 

 sequence ; while soil texture and nature of subsoil deserve most consideration, 

 in that they determine the suitability of the soil as the abode of the 

 plant in respect of moisture-supply, air-supply, and temperature. On local 

 climate depends to a considerable extent the suitability or otherwise of 

 a soil area to the growth of various kinds of agricultural plants. 



The various methods of soil-classification hitherto proposed may now 

 be considered. According to Tulaikoff,* all classifications of soils yet pro- 

 posed may be divided into two groups : (a) scientific classifications, which 

 are based on the natural characteristics of the soil; and (b) "applied" 

 classifications, which are based on the suitability of soils for certain crops, 

 or on the revenue that may be derived from them. In New Zealand the 

 practical man uses such an " applied " method when he loosely classifies 

 land as (1) dairying land, which comprises the heavier soil with a rainfall 

 of, say, over 25 in. ; (2) sheep country, which comprises hill pastures 

 inaccessible to the plough, as well as the "lighter" and drier soils at lower 

 levels ; (3) cropping land, intermediate between these. 



According to the features on which the study of soils is based, the 

 "scientific" classifications are divided into — (1) the geologico-petrographical, 



* N. M. Tulaikoff, The Genetic Classification of Soils, Journ. Ag. Sci.. vol. 3, 1908, 

 p. 81. 



