IRRIGATION IN FIELD AND GARDEN. 



BY PROFESSOR E. J. WICKSON. 



(Reprinted from Farmers' Bulletin No. 138, issued by U. S. Dept. of Agriculture. 

 DISTRIBUTION OF IRRIGATION WATER. 



For the conveyance of water from the source of supply to the 

 ground to be irrigated, as well as its distribution thereon, the ditch is 

 the prevailing agency. The laying out and constrction o ditches 

 has been already discussed. ., 



Their obvious advantages are cheapness and durability. The 

 chief disadvantage lies in the loss of water by evaporation and seepage. 

 Where the water supply is scant and where the soil is so open that 

 the loss of water by seepage is likely to cause injury to good land or 

 lower levels, the savings of these losses may justify the expenditure 

 necessary to prevent seepage by paving or cementing the ditch, or to- 

 insure delivery of water without loss from any cause by the use of a 

 pipe line. These are usually questions connected with large irriga- 

 tion enterprises rather than with the use of a farm supply, and yet 

 they sometimes arise in connection with the latter. In regions where 

 the ground does not freeze a thin coating of cement or asphaltum on 

 well-made ditch banks and bottoms will prevent all losses from seep- 

 age. Where flat stones are plentiful, they are readily made into a 

 stone ditch with cement mortar. Such ditch linings are, however,, 

 liable to be upheaved by freezing and are safe only in moderate win- 

 ter climates. 



The board flume is upon the whole the most available recourse 

 when the simple open ditch will not answer, and the cheapest flume 

 for carrying a small stream of water is the V-shaped trough of two 

 wide boards nailed together along two edges and bedded in the soil 

 with shoot cross-pieces under the end joints This prevents loss of 

 water by seepage, reduces friction, and delivers the water rapidly 

 with a very slight fall and escapes the erosion of a dirt ditch if the 

 slope is sharp. Even where the water must be carried over an un- 

 even surface in a flume supported by stakes and cross-pieces, the 

 bedded V-flume is still desirable for the parts where a good grade in 

 the earth can be found. 



The various ways in which water is distributed for the growth of 

 fruits, according to the slope of the ground and character of the soil, 

 have been discussed in such detail in Farmers' Bulletin No. 116, that 



1 See also Yearbook U. S. Department of Agriculture, 1900, p. 492. 



