THE IKRIGATION AGE. 



553 





on lands of comparatively small value. As lands increase 

 in value and methods improve, these meadows 'are re- 

 seeded to finer grasses and more care is used in irrigation. 

 If the practice of wild flooding is retained at all, the 

 meadow is left under water for short periods only, of a 

 few hours to a week in duration. 



Flooding From Field Ditches. 



This is usually known simply as "flooding," and is 

 perhaps the most widely used of all methods, especially 

 in the newer irrigated districts. The ditches are most 

 commonly run parallel to the slope, irrigation taking place 

 from only one side of the ditch and extending to the next 

 ditch. Sometimes on nearly level land the ditches are 

 run down the steepest slope, irrigation taking place from 

 both sides and extending midway between ditches. Under 

 either method the distance between laterals should not be 

 over 200 feet, and it is better to have them closer together. 

 Irrigation is easier and more uniform if the laterals are 

 only 50 to 100 feet apart, though, of course, it is then 

 necessary to have more field ditches, each one of which 

 takes out some crop-growing area from the field. For 

 valuable crops, however, the advantage lies with the closer 

 spacing of the ditches. These field ditches may be either 

 temporary or semi-permanent. With annual crops, such 

 as grains, the common practice is to plow and harrow 

 over them, remaking them each year. This is more con- 

 venient, as the drills and other farm implements can then 

 be driven across the field without interference by the 

 ditches. It entails the extra work of listing put and trim- 

 ming the ditches each year. Permanent ditches should 

 also be repaired and trimmed each year, for if this is not 

 done, they are very apt to become irregular, cut out in 

 places, and stopped up with vegetation in other places. 

 The common lister and the V-shaped crowder or "Go- 

 Devil," are the implements commonly used in making 

 field ditches. The "A," or "Go-Devil,' is easy to con- 

 struct, and can be adjusted to make various widths of 

 ditches. In preparing ground for this kind of irrigation 

 it should be brought to a uniform slope by means of 

 scrapers and home-made levelers, or some other levelling 

 device, as the labor of irrigating each year will depend 

 on how well this has been done. This method is in gen- 

 eral suitable for medium slopes, soils which do not bake 

 or crust badly after flooding, grains, meadows and hay 

 crops, and for the extensive system of farming, where 

 lands are not of great value, and such crops as require 

 comparatively little attention are raised. While in first 

 outlay the expense necessary is not large, the annual cost 

 for irrigation is usually excessive. From two to five acres 

 a day is as much as one experienced irrigator can thor- 

 oughly water, and as a rule the irrigation is more uneven 

 than with other methods. This causes uneven ripening 

 of the crops, which is, of course, a disadvantage. 



The Furrow Method. 



There has been a demand for a method of irrigation 

 which does not flood the "crown" of the crop plants, and 

 also one which would not produce baking and cracking 

 of the surface soil, so prevalent with heavy clay soils 

 under the flooding methods. The furrow method accom- 

 plishes this. The seepage of water from the side of the 

 small ditch or furrow outward to the crop, or "subbing," 

 is maintained. Various modifications of the furrow meth- 

 ods are used to adapt it to different conditions of soil, 

 crop, or head of water used. For grain drilled in rows 

 eight inches apart it is usual to make the furrows narrow 

 and deep, four to five inches wide, three to four inches 

 deep, and twenty-four to thirty-two inches apart. For 

 alfalfa and other drilled hay crops the practice is much 

 the same; the furrows being perhaps n little larger. T'ne 

 head ditches or laterals between which the furrows are 

 run should not be over 200 feet apart, as a general rule. 

 That is, the furrows should not be so long that the 

 water will not run through from end to end in a reason- 

 able time, say half an hour to an hour. They should 

 be long enough, so the water will have time to "sub," 

 or seep to the side and dampen all the soil between the 

 furrows. The best length will depend on the soil, the 

 slope, the size of. and distance between the furrows. 

 Tt is determined by the individual farmer for his own 

 conditions without great difficulty. 



Root crops are almost always found to do best under 

 the furrow system. Potatoes, especially, show the bad 

 effects of even a break between the furrows, and con- 

 sequent flooding. In this case the furrows are made 

 quite large, the rows being ridged, and one furrow be- 

 tween each two rows. Sometimes, the best method for 

 the crop and the most economical of water, is to irri- 

 gate only alternate furrows, as with sugar beets and 

 potatoes. The land cultivation, thinning, etc., can then 

 be done from the dry rows more conveniently. The 

 furrow system is coming to be widely used for irri- 

 gating orchards. 



The method of dividing the irrigation streams be- 

 tween a number of small furrdws varies in different 

 localities. At Twin Falls, Idaho, and a number of other 

 progressive irrigation districts, what is called the "lath 

 box" system is used. In this system boxes are made 

 by placing four strips of wood, as common plastering 

 laths cut in half, together and nailing them so as to form 

 a narrow, square-section box which may be used as a 

 pipe to admit water through the lateral bank to the 

 upper end of the furrow. The boxes are placed in the 

 ditch banks at each furrow and are easily closed by a 

 stopper formed of a short piece of lath, or by a small 

 square of tin tacked by one corner over the opening. 

 The most common method in all probability is that of 

 depending on the irrigator to open and close the head of 

 the furrows by means of a shovel and some dirt. Some- 



The Big Horn River in Wyoming is a Grand Strfani. 



times a flume or trough, or pipe, is used instead of laterals, and 

 holes at proper distances, easily opened or closed, serve 

 to regulate the flow into the furrows. For valuable land, 

 these methods are proving a success, and when the 

 preparation has been completed, the actual labor of irri- 

 gation is reduced to supervision of the flow in furrows, 

 and regulation of the little head gates. 



Check Method. 



This is simply a modified flooding method by which 

 the water is retained at some depth on the land, as long 

 as the irrigator thinks best, instead of being spread out 

 by hand labor while running, as in flooding. This is 

 accomplished by means of small dikes or levees thrown 

 up, either in rectangular, or square form, or along con- 

 tour lines. The square system makes the fields take on 

 somewhat the appearance of a gigantic checker-board, 

 whence the name given this method. The check system 

 is best suited to land having very little slope. On 

 practically level ground the banks may be placed far 

 apart. In parts of Arizona and New Mexico on such 

 land they may be as much as a half mile apart, thus 

 inclosing a quarter section in a single "check." But in 

 general the "checks" or squares are very much smaller, 

 often containing less than a quarter acre. 

 (Continued in October.) 



