190 IRRIGATION. 



parts of the country where cultivation by irrigation is 

 now practiced, and where it is destined to be largely ex- 

 tended, admit of very easy preparation by plowing, har- 

 rowing, scraping, and rolling. To plow these lands, a 

 different system from that generally practiced should be 

 adopted. The swivel plow is the best instrument for this 

 purpose. "With this plow, the furrows may be laid the 

 same way over a whole field, and the " lands," more or 

 less narrow, necessarily formed with the common plow 

 are avoided. In plowing in " lands" the alternate back 

 furrows and open furrows leave a succession of ridges and 

 hollows, which are inconvenient in irrigated fields, except 

 in those cases in which the system of "bedding" of the 

 soil is adopted. In this case the water is carried along 

 the summits of the lands, and flows in both directions to 

 the open furrows on each side. This may be convenient- 

 ly done when the general level is once secured. 



A good surface will be best secured by using the swivel 

 plow, beginning by running a back furrow across the 

 center of the field, carefully laid out exactly parallel to 

 two of its sides if the field is square and equally dis- 

 tant from each. The back furrow should be made by 

 first throwing two furrows outward in opposite directions, 

 leaving an open furrow on the line laid out. The plow is 

 then driven through the center of the ridges thus cast 

 out, splitting them and throwing the earth back into the 

 open furrow. This method leaves no unplowed ground, 

 and very much less ridge in the back furrow than any 

 other manner of beginning the "land." The plowing 

 then proceeds in the usual manner, finishing one side of 

 the field, and then the other. If care is taken to plow 

 straight and even furrows, the last furrow will leave a 

 ditch along the boundary of the field, and close to it. 

 There should be no baulks made in plowing an irrigated 

 field, as the hard spots there left will not absorb water 

 equally with the other portions, and the crop will suffer 



