THE IEKIGATION AGE. 



21 



Injurious Results from Excess Use of Water in 

 Irrigation. 



In the following extract from a report by W. P. 

 Snycler, Superintendent of the North Platte substa- 

 tion, Nebraska Experiment Station, the limits to bene- 

 ficial application of water in irrigation and the in- 

 jurious results arising from excess use are pointed out 

 in a clear and convincing manner : 



SOIL CAN CONTAIN ONLY A LIMITED AMOUNT OF WATER. 



A sandy loam soil when very dry contains. 6 per 

 cent or more moisture. Ordinary crops deplete mois- 

 ture in a sandy loam soil to only 9 or 10 per cent in 

 the first 4 or 6 feet. The ordinary sandy loam soil, 

 when saturated with water, contains about 16 per cent 

 of moisture. A coarser soil contains less and a finer, 

 heavier soil more than this amount. However, the 

 heavy soil will withhold from the crop a much higher 

 percentage of moisture than the lighter soil. Also the 

 plants feed more deeply in the lighter soil, so that the 

 amount of available water that may be stored in vari- 

 ous soils does not vary greatly. One per cent of mois- 

 ture in the first 6 feet of the soil is approximately 

 equal to one inch of water. 



Since the maximum amount of water a sandy 

 loam will retain against gravity is about 16 per cent, 

 and since the ordinary crop draws this down to only 

 9 or 10 per cent and since 1 per cent in 6 feet of soil 

 means about one inch of water, it is obvious that there 

 can be stored at any one irrigation only about 6 or 7 

 inches of water on a field growing a crop. This is 

 allowing a maximum amount of water. Under most 

 conditions one-half of this amount would be enough 

 to saturate the feeding ground of the plants. If the 

 soil is very dry, as alfalfa land or native grass land, 

 then possibly 10 inches may be stored. If more water 

 is added it goes deeper than 6 feet and is not readily 

 available to the crop. 



Why put on more water than the soil can use? 



TOO MUCH WATER AN INJURY. 



First: It washes out plant food. Nitrogen is 

 the plant food element that the western soil is most 

 deficient in. It is easily washed out. If washed be- 

 low the feeding ground of plant roots, it is lost. 



Second : Clogs the surface few inches of soil by 

 cementing the small particles together and thus pro- 

 ducing puddling, which all recognize as very injurious 

 to soil. 



Third : It crowds out air. This lessens :the 

 action of bacteria in making plant food. 



Fourth : It lowers the temperature of the soil. 

 This retards growth. The seasons are too short in 

 the northern states, and growth should be hastened. 



Fifth: The excess water that goes into the soil 

 comes out somewhere. It often seeps out on the land 

 lower down and injures it or even destroys its use for 

 agricultural purposes. 



Sixth : Water has a value the same as any other 

 material. No man has a right to more than he uses 

 properly. If he uses more than he needs or wastes 

 it he is using something that does not belong to him. 



Send $1.00 for 1 year's subscription to the IRRIGA- 

 TION AGE and bound copy of THE PRIMER OF IRRIGA- 

 TION. If you desire a copy of The Primer of Hy- 

 draulics add $2.50 to above price. 



STUDY OF THE SOILS. 



"No industry is so vital to the well-being of a 

 nation as agriculture, and nothing is so vital to agri- 

 culture as the soil. From its treasury it has been 

 estimated that we drew during the year 1909 more 

 than $8,296,000,000, and its possibilities are as yet 

 only partially realized. There are still in this coun- 

 try millions of acres which have never felt the plow, 

 while those which are now under cultivation can, 

 by the application of scientific principles, be made 

 to produce many times the present value of their 

 products. How to use and not abuse this great re- 

 source is the most important problem which faces 

 the farmer of today one worthy of the best efforts 

 of our most profound and learned scientists; for 

 upon its solution depends the future prosperity of 

 the nation." 



The above is a statement from Bulletin 85 of 

 the Bureau of Soils relative to the soils of the coun- 

 try. While a comparatively small percentage of the 

 soils of the United States have been surveyed and 

 analyzed by the Department, more than 800 types 

 of soils have been discovered during the progress 

 of the soil survey. The existence of such a large 

 variety of soil types, each possessed of definite and 

 peculiar characteristics, calls attention to the im- 

 portance of a careful study of the soils and their 

 relation to agriculture. The Bulletin says : 



"The old idea of soil investigation was to col- 

 lect samples, examine them in the laboratory, and 

 see what differences could there be determined; the 

 newer idea is to study the characteristics and prop- 

 erties of soils in the field, classify them according 

 to obvious differences, and, with this information in 

 hand, use the laboratory as a means of ascertaining 

 the cause of such variations as cannot be determined 

 in the field. This method of attacking soil problems 

 is the reverse of the usual practice, but because of 

 the great difficulty in duplicating field conditions, it 

 is believed that a field examination should precede 

 laboratory studies. The field observations can thus 

 be used as a check upon laboratory investigation 

 and as an aid in their interpretation. Field studies 

 furnish a safe and necessary anchor with which to 

 keep the laboratory experimenter from being dashed 

 against the rock of pure speculation. The classify- 

 ing and mapping of the various soil types, together 

 with the study of the conditions and processes un- 

 der which they have been formed, will furnish essen- 

 tial and invaluable data for the conduct of labora- 

 tory investigations. Nature's great laboratory is in 

 the field, and a study of her methods cannot fail to 

 offer many valuable suggestions, and, in some cases, 

 is the only means of solving her problems. It is 

 through a combination of field and laboratory in- 

 vestigations that an understanding of this extreme- 

 ly complex body the soil can be reached." 



The Bulletin treats exhaustively the soils, their 

 origin, formation and best treatment for agricul- 

 tural purposes, the great difference between the 

 many types, and adds : 



"Since the soil varies so much as regards both 

 its inorganic and organic constituents, marked dif- 

 (Continued on page 26.) 



