186 EXPERIMENT STATION RECORD. [Vol.37 



lauds have been built up with Santa Ana sewage by applications of approxi- 

 mately 8 in. every 30 days for two years before planting to sugar beets to 

 maintain the fertility. It is estimated in this case that " sewage irrigation 

 increases the yield of beets 3 to 4 tons per acre over clear-water irri- 

 gation. . . . 



" The sewage farm should be considered as a large receiving bed and a part 

 of the purification system, upon portions of which the sewage is intermittently 

 spread and where purifying takes place through the action of the soil bacteria 

 and .sunlight. For this reason an efficient distribution system on the farm 

 is as important as any part of the plant. Every small stream of sewage should 

 be under absolute control and a rotation of irrigation followed which will not 

 overload any portion of the land and hinder the purification proce.s.ses or the 

 growth of crops. The bacteria dangerous to health may be destroyed by 

 chemical treatment of the effluent from .septic tanks, but this should not be 

 neces'sary if proper precaution is taken to prevent the sewage getting into 

 drinking water or coming into contact with vegetables which are to be eaten 

 without cooking. . . . 



"One of the chief causes of failure in .«ewage irrigation in the Unite<l States 

 is the lack of proper irrigation construction and management on the farm. 

 Open ditches .still unfortunately prevail on sewage farms. These ditches are 

 the greatest source of offensive odors due to the dangerous accumulations of 

 putrefying matters which collect wherever there are weeds, pockets, or dead 

 ends. Seepage from earthen ditches is apt to be large in porous soils and 

 dangerous to the public health. The continuous control of sewage in ditches 

 and an efficient division into irrigation units can best be obtained with a pipe 

 and hydrant system. . . . The management of the sewage irrigated farm 

 is a vital an<l serious problem upon which the success of the project depends." 



Irrigation studies, Ontario and Covina [California], U. S. Vaile (Cal. 

 Citrogr., 2 (1911), So. 5, pp. 9, 10. fifjs. S). — Irrigation experiments with citrus 

 orchards on comparatively open gravelly soil with a very pervious sub.soil of 

 coarse gravel at from 3 to 8 ft. are reported. The following conclusions were 

 drawn as to economic methods of irrigation on the.se soils : 



" Irrigation districts should be so far reorganized as to accommodate more 

 frequent delivery of water to users. It is somewhat doubtful if more total 

 water may be used to advantage provided the Interval is reduced, although the 

 data submitted does not entirely establish this point. Neither is It clear 

 that In days is necessarily the correct Interval. . . . Shorter furrows should 

 be provided as rapidly as economic conditions justify." 



It is further considered advisable to mulch the lower few rows of tn»es to 

 prevent run-off and conserve moisture at that point. 



Drainage as a correlative of irrigation, C. G. Elliott (Trans. Intcmnt. 

 Engin. Cong., 1915, Wntrrvnyg and Irrig.. pp. 510-529, flgn. 7). — It is the pur- 

 pose of this paper to correlate the practices of Irrigation and drainage "ami. 

 particularly, to show the methods of <lraining wet lands under irrigation as 

 now successfully practiced in this country." Special attention is given to the 

 work of the Drainage Investigations of the U. S. Department of .\grlculture 

 along this line, as formerly conducted under the supervision of the author. 



Flood control for Pecatonica River (///. Rivers nnrl J.nkes Com. Bui. /S 

 (19lfi). pp. S.f. p7.t. 2. figs. 22). — This bulletin is compiled from the results of 

 investigations made by the Illinois Rivers and Lakes Conunission an<l the U. S. 

 Geological Survey Into the flood conditions of the Pecatonica Valley. 



It is concluded " that the river, in Its natural state, spreads out over the 

 whole valley during flood periods, and the tendency Is toward a general In- 

 crease of Hood height and property damage due to the silting up of the channel 



