﻿UNITED STATES DEPARTMENT OF AGRICULTURE 



DEPARTMENT BULLETIN No. 1139 



Washington, D. C. PROFESSIONAL PAPER April 14, 1923 



STORAGE OF WATER IN SOIL AND ITS 

 UTILIZATION BY SPRING WHEAT. 



By O. R. Mathews, Assistant Agronomist, with Introduction by E. C. Chilcott, 

 Agriculturist in Charge, Office of Dry-land Agriculture Investigations, Bureau 

 of Plant Industry. 



CONTENTS. 



Page. 



Introduction 1 



Sources of information 2 



Range of moisture content of soils 3 



Manner of study 5 



Classification of data 7 



Page. 



Conditions at individual stations 14 



Average of results for all stations 19 



Comparison of cultural methods 23 



General conclusions 24 



Summary 26 



INTRODUCTION. 



The work of the Office of Dry-Land Agriculture Investigations 

 covers many stations and consequently a wide range of soils and cli- 

 matic conditions. It has been continuous at these stations for a rela- 

 tively long term of years. It consequently offers exceptional oppor- 

 tunity for the generalization of data and the drawing of conclusions 

 based on the average conditions of soil, location, and season. This 

 possibility of generalization does not preclude or interfere with the 

 recognition of the extremes of individual conditions, but makes it 

 possible to assign to them their relative importance in the make-up 

 of the whole. 



The water-storage capacity of a soil and the depth to which crops 

 are able to use the stored water are matters of prime importance. 

 Other conditions being equal, the soil that will hold the greatest 

 quantity of water within reach of plant roots should show the most 

 material benefits from methods of cultivation calculated to conserve 

 and accumulate soil moisture. It usually happens in the Great 

 Plains, however, that the water-storage capacity of the soil is only 

 partially used. During the greater portion of the time on most soils 

 the quantity of water held in the soil is limited by the amount of 

 water available for storage rather than by a lack of storage capacity. 



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