60 



of Avator into the atniosphoro. (irtidiiioor loveling- tlie surface is even 

 more important, since it is ditHciilt to a})piy water to an uneven sur- 

 face, the growth of the crop is not uniform, and the soil in the low 

 places is likely to l)e damaged ]>y an excess of water. 



The time necessary to matui'e plants ditiers. Under favoral)le con- 

 ditions a crop of alfalfa can ])e grown in less than iift}' days, a crop 

 of l)arle3' in something over one hundred days, while it may require 

 one hundred and tifty days to ripen certain varieties of fruit. There 

 is not only a ditierence in the period of growth, but also in the number 

 of crops grown in one season. 



The way in which water is applied is perhaps as important as the 

 quantit}^ used. Some soils bake after l)eing flooded and furrow irri- 

 gation nmst be used for all crops. Other soils are so porous that 

 furrow irrigation is not practicable. In irrigation l)y flooding, as 

 generally practiced in Montana, care is usually taken to distribute the 

 water during the day, but it is left unattended during the night. 

 Full}' 20 per cent of the available supply may be wasted while the 

 irrigator sleeps or is off dut3^ 



A part of the Gallatin Valley is underlaid by coarse gravel and col)- 

 bles and a large percentage of the water applied to the surface sinks 

 into these porous materials and drains down the valle}". Other por- 

 tions are undulating, which renders the application of water somewhat 

 difticult. 



In the Bitter Koot Valley much of the fruit soil is light and porous, 

 and is located for the most part on steep slopes. For these reasons 

 the amount of water used is considerably above the average. Along 

 the Milk River Valle}' the slope is flat and the soil somewhat heav}'. 

 These conditions favor a high duty, and when this part of the State is 

 further developed it is expected that a cubic foot per second will be 

 sufficient for 100 acres. 



It frequently happens that fields which have received large quanti- 

 ties of water produce low yields. This result ma}' be due to one or 

 more of a large number of causes. Chief in importtmce is the proper 

 cultivation of the soil. It may be regarded as one of the fundamental 

 truths in agriculture that irrigation can not take the place of cultiva- 

 tion. The western irrigator has been slow to recognize this fact, and is 

 still inclined to depend too much on irrigation and too little on cultiva- 

 tion. Asa rule, in ^Montana the largest and most profltable A'ields are 

 obtained from the use ot" a moderate amount of water. The people of 

 Gallatin \'alley, who produce the largest yield of grain in the State, 

 use the least amount of water in irrigation. 



Throughout th(> most productive regions of the State suflicient water 

 is diverted to coxer the land watered to d -])ths varying from 8 to 5 

 feet, but since a large percentage is lost in transit the volume which 

 reaches the flelds would not cover them to depths greater than 20 to 



