THE MONTHLY BULLETIN. 233 



danger attaching to the inadequate use of irrigation water which is 

 greater than that accompanying the use of water too freely, or in too 

 large a quantity? This question I must answer as follows: Users of 

 water do not realize that the internal surface of soil is so enormous that 

 even in a well-drained condition deep soils, such as those which we have 

 in this State, possess a capacity for water which makes a small percent- 

 age of that material in the soil quite sufficient for the production of 

 a large crop, for the reason ahove given, namely, that the roots can 

 cover so large a surface of soil particles, vertically and horizontally, 

 that they obtain more water than they would in a thin layer of soil 

 with a water-logged subsoil beneath. To emphasize the great extent 

 of the internal surface in soils, I need but say that it will vary from 

 the coarse sandy soils to the clay loams or clays in an acre four feet 

 in depth from approximately 50 square miles to 300 or more square 

 miles. The more of this total area it is possible for roots to grow upon, 

 the more water and food they will obtain and the larger and more 

 vigorous will the root systems become. While it is true that from three 

 to six hundred tons of water are necessary to produce one ton of dry 

 matter, for average plants a ton of water is but a very small quantity 

 in an acre of soil, and therefore while six tons of alfalfa hay per acre 

 would probably need as much as 3,000 or more tons of water for its 

 production, it must be remembered that 3,000 tons of water, when 

 scattered through a layer of soil only six feet in depth (and our alfalfa 

 plants feed at very much greater depths) in our normally deep soil, 

 will make but a small percentage of water in soil, which will, of course, 

 vary with the fineness of the soil grain. 



Our great problem, therefore, is not to fill the soil with water, but, 

 having a moderate amount of Avater there, to conserve that water. 

 There should be more cultivation and less irrigation; there should be 

 more surface mulching of soil and less irrigation ; there should be more 

 incorporation of organic matter, either from barnyard manure, gi'een 

 manures, or other forms, thus giving the soil a larger water holding 

 power at any one irrigation, and the number of irrigations should be 

 decreased to a minimum. Whatever we lack of information relative to 

 engineering methods l)y which more rational systems of irrigation may 

 be instituted, we must admit that we possess enough information other- 

 wise which teaches us to employ water very sparingly and never to 

 make possible the further rise of a dangerously high water tal)le, the 

 accumulation of alkali, the inactivity of beneficial soil bacteria, the 

 quick formation of clay and the cutting down of the surface upon 

 which roots may feed. By such methods we shall make possible the 

 production of as big crops as our good ones of today or bigger by the 

 use of many times less irrigation water and with a decreased cost of 

 applying water. Moreover, what is far more important, we shall thus 

 make possible the maintenance of fertility in soils, prevent in anywise 

 the impairment of their producing powers, the decrease in their depth, 

 and their optimum use as media for plant root development which, to 

 so large a degree, determines the development of the above ground 

 parts of plants. 



I trust that I have made clear the arguments in favor of more careful 

 application of water to soil, because I deem that one of the most import- 

 ant things for the water user to bear in mind, if he desires to maintain 



