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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