THE IRRIGATION AGE. 



273 



greater the demand for all that the merchant has 

 to sell, and all that the farmer is producing. The 

 longer the region is cultivated, the more evident it is 

 likely to become that much can be accomplished along 

 the lines of material progress, by more diversified and 

 more intensive farming. 



METHOD OF IRRIGATING CROPS. 



Most irrigating is done in the region by one of two 

 methods through furrows, or by flooding. The fur- 

 rows may be permanent or temporary. Plants such ag 

 strawberries and small vegetables that require the fre- 

 quent application of small amounts of water are by 

 most growers irrigated through furrows that are more 

 or less permanent. Some farmers break up by cultiva- 

 tion the crust that forms on the surface, while others 

 simply hoe from the furrows and the intervening ridges 

 the weeds that grow there. This method of irrigation 

 should be resorted to only in the case of such crops and 

 under such climatic conditions as to make it difficult to 

 irrigate by any other method. 



Running water through temporary furrows that are 

 cultivated up after each irrigation is to be preferred 

 wherever practicable. Experience at the farm shows 

 that this is the method by which all crops that can be 

 so irrigated should be irrigated. The water applied 

 penetrates the soil, and a smaller percentage is lost by 

 evaporation than by any other method. Since the soil 

 mulch formed by cultivation prevents the rapid escape 

 of moisture, crops will need less frequent irrigation by 

 this method than by any other. 



In irrigating by the furrow method it is important 

 that the streams permitted to run in the furrows be 

 small. Just enough water to cause the stream to creep 

 slowly along should be turned down each furrow. The 

 soil will thus become thoroughly saturated and little 

 water will escape at the lower end of the field. The 

 more slowly the water makes its way down the furrows, 

 the better, provided it gets through during the time that 

 irrigating water is available. If so large a stream is 

 permitted to run in each furrow that the water reaches 

 the lower end quickly, the sides are thus made less per- 

 vious, and a large percentage of the water escapes at 

 the lower end water that would percolate into the soil, 

 if it ran more slowly. For equalizing the flow of water 

 into the upper ends of the furrows, straw or other 

 similar coarse material will usually be found service- 

 able. If something is not used to prevent the washing 

 of the soil, the tendency is for too much water to find 

 its way down some furrows, and too little down others. 



In the case of crops that cover the ground, such as 

 alfalfa and grains, flooding is the method in general 

 practice. In this region these crops are flooded by run- 

 ning a large stream of water between two ridges (com- 

 monly called "borders") thrown up with a plow, about 

 thirty feet part. Between these two ridges the water 

 being applied spreads out into a broad shallow stream 

 that flows the length of the field. Waste ditches at the 

 lower end of the field carry off water that flows from 

 the ends of the lands. The first time a field is irrigated 

 after sowing, and to some extent at later irrigations, it 

 is necessary to impede the progress of the stream of 

 water and cause it to spread over the whole surface, 

 where, on account of the slope of the land, it is inclined 

 to run in a narrow stream. This is done by throwing 

 up across its course earthen ridges called "tappoons." 

 If these tappoons are properly made they will usually 

 cause the water to flow where it is desired during sev- 

 eral subsequent irrigations. 



Before plowing unoccupied land it is commonly 

 irrigated by flooding. Experience at the farm shows, 

 however, that a better way is to run the water through 

 furrows made two to three feet apart, the distance 

 apart depending on the nature of the soil and the length 

 of the field. The more slowly the soil takes water, 

 and the shorter the field the nearer together the furrows 

 need to be. At the farm these furrows are made with 

 an adjustable three-shovel furrower, by means of which 

 the land can be furrowed as rapidly as it can be ridged 

 ("bordered"). Less water is required by the furrow 

 method, less labor is required to handle the water, and 

 less water is lost by evaporation. Moreover, the whole 

 surface of the soil does not become crusted over or 

 baked as it dries, as does land that is irrigated by flood- 

 ing. In some cases land may be too hard to furrow, and 

 flooding be therefore necessary. 



In discussing the irrigation of individual crops in 

 the pages that follow, the methods recommended are 

 those that experiments at the farm indicate are best. 



Alfalfa seed may be sown in dry soil or soil that 

 has been previously irrigated, the latter method being 

 usually preferable. It is better to have the soil in such 

 condition as to moisture and tilth that the seed will 

 germinate and the young plants appear without further 

 irrigation being necessary. If the soil was dry when 

 the seed was sown, or is not sufficiently retentive of 

 moisture, or if, on account of the nature of the weather 

 that follows seeding, the soil dries before the plants 

 appear, water should be applied as promptly as prac- 

 ticable. The young plants must have plenty of water 

 in order that a good stand may be secured. 



The seeding may be done at any time during the 

 period from October to March inclusive, but the best 

 times are October 1st to November 10th and January 

 loth to the end of February. The young plants being 

 sensitive to both low temperatures and excessive heat 

 and aridity, a good stand can best be secured from the 

 use of a given amount of water by sowing during the 

 seasons above recommended. 



After the young plants appear, they should be 

 given water frequently enough to keep them growing 

 steadily. The application of water twice a month, dur- 

 ing the first three months is usually ample to secure a 

 good stand. If sown during the winter season men- 

 tioned above, a light crop may be cut three or four 

 months after sowing. After this, the application of 

 water once a month is sufficient the first season. It is 

 probably not economical to apply much water during 

 November and December, but beginning with January, 

 water may be applied freely to advantage, under the 

 conditions existing in the region of the farm. Where 

 water is available at all times of the year when needed 

 for alfalfa, it will probably be better in most cases to 

 postpone the free application of water until the first 

 of February. Alfalfa being very deep-rooted, water to 

 the depth of two feet may be applied to advantage just 

 before, or during the early part of the growing season. 

 After cutting the first crop, water may still be applied 

 freely to advantage. After cutting the second crop the 

 application of one-half to two-thirds of a foot of water 

 will be sufficient for the production of each subsequent 

 crop. But the amount that will be necessary to secure 

 a good growth during the summer will depend very 

 much upon the amount applied during the winter. If 

 the field has been thoroughly wet during the latter sea- 

 son, two good crops can usually be cut without irriga- 



