THE IRRIGATION AGE. 



37!) 



alkali, and creates disease. Nearly every irrigated dis- 

 trict in the West has its abandoned farms which have 

 been rendered non-productive by an excessive use of 

 water. Alfalfa fields which were at one time worth 

 $100 per acre, vineyards which sold readily for $350 

 per acre, and orange groves that gave large dividends 



A peep into the woods of western Oregon. 



on a valuation of $1,000 per acre, may now be pur- 

 chased for from $10 to $30 per acre. The accumulation 

 of seepage waters caused by over-irrigation and leaky 

 ditches with all its accompanying evils'has already dam- 

 aged about 10 per cent of the irrigated lands of the 

 West. 



THE MOISTURE REQUIREMENTS OF CULTIVATED PLANTS. 



The thirst of the plant must be satisfied in order 

 to maintain a vigorous growth, but this does not mean 

 a complete saturation of the soil around its roots. 

 Plants require air as well as water, and if other condi- 

 tions are favorable a comparatively small percentage 

 of moisture in the soil will suffice. Ten pounds of free 

 water in each one hundred pounds of soil is ample for 

 most crops. By "free water" is meant the soil moisture 

 which the fibrous roots absorb and which a hot sun is 

 capable of evaporating from the soil. The application 

 of four inches of water over the surface of a field on 

 which plants arc growing fairly well furnishes suffi- 

 cient moisture for four feet of soil, providing it is 

 evenly distributed without loss. Most of the troubles 

 of the irrigator arise from his not being able to either 

 apply or distribute this water evenly and without loss. 

 Good soils and subsoils are never water tight. If they 



. were impervious to the downward passage of water they 

 would not produce crops. The irrigator is thus obliged 

 to spread water over a more or less porous mass which 

 may permit a large part to pass through it. If he at- 

 tempts to keep the water for any length of time near 

 the surface, it will speedily pass off as vapor into the 

 atmosphere. His task, therefore, approaches in diffi- 



culties that of keeping water in a vessel with both ends 



open. On the one side is a layer of warm, dry air, 

 ever ready to suck up moisture; on the other, is a 

 porous subsoil through which water is drawn by force 

 of gravity. To guard against these and numerous other 

 losses of irrigation water, the Western farmer must 

 possess more accurate knowledge of the frequency and 

 extent of the chief sources of waste. It is not enough, 

 for example, to spread a certain volume of water over 

 a field. He should endeavor to find out how much of 

 this volume passes through the subsoil and collects, 

 it may be, in his neighbor's low lying tract where the 

 alkali salts are rising to the surface, and how much 

 passes off into the atmosphere from the surface of the 

 soil during the interval between irrigations. 



THE CHIEF SOURCES OF WATER WASTE. 



By beginning with the losses which take place on 

 the irrigated field and tracing other losses back through 

 a network of ditches and canals to the source of supply, 

 I hope to convince you that for every four gallons 

 taken from the stream, little more than one gallon 

 subserves a useful purpose in nourishing crops. 



You will admit, I believe, that water is more 

 skilfully applied and more economically used in south- 

 ern California than in any other portion of the West, 

 and perhaps of the world. The Office of Experiment 

 Stations, at Washington, is now printing some results 

 of experiments in evaporation losses conducted last 

 year in the vicinity of Riverside, California. We se- 

 lected for our investigations the lands under the Gage 

 Canal, which irrigated last year 8.500 acres of 'orange 

 and lemon orchards, and we chose for our experiments 



MR. J. H. KURTZ, Ephrata, Pa. 



Delegate to Fourteenth National Irrigation Congress. 



Hon. Vice-President lor Pennsylvania. 



some of the most skillfully irrigated tracts in that large 



area. 



I may say in passing that the average duty of 

 water on the orchards under the Gage Canal for the 

 past even years has been 25 inches and the irrigation 



