AGRICULTURAL ENGINEERING. 581 



Rpt. 1893^ pp. 177-179). — In continuation of experiments briefly reported 

 in Bulletin 26 of the station (E. S. R., 5, p. 690), 1 row of 16 grapevines 

 was subjected to surface irrigation and another, containing 17 vines, 

 to subirrigation. For the latter purpose a wooden tube, 4 in. square 

 inside, was laid in a trench 1 ft. below the surface and 1 ft. from the 

 vines. Water was supplied to the roots of each vine by 2 three-fourths 

 inch holes bored in the tube opposite the vines and protected from dirt 

 on the top and sides by boxing in. In irrigating the pipes were kept 

 filled with water until the ground began to show the effects on the sur- 

 face. This usually took from 1 to 2 hours. 



"So far as the production of fruit is concerned the results are favorable to sub- 

 irrigation. The yield for 1892 was 36J lbs. for the 16 vines under surface irrigation 

 and 3.»i lbs. for the 17 vines under subirrigation, there being no effect noticeable. 

 The yield for 1893 was 53| or 3.36 lbs. per vine for the surface irrigation, and 76| or 

 4.52 ll)s. per viae for the subirrigated portion." 



Determinations of the water content of the soil before irrigation and 

 30 aiul 54 hours after irrigation directly over the tubing, and 1, 2, 3, 

 and 4 ft. from the tubing showed that at a distance of 2 ft. from the 

 tubing the water content was but slightly increased and at distances 

 of 3 and 4 ft. it was not affected. 



An attempt to substitute V-shaped troughs made of 6-inch boards, 

 placed bottom side up in the trench, was not successful on account of 

 the filling of the drain at the lower end with dirt. 



Fall vs. spring irrigation, J. W. Sanborn ( Utah Sta. Kept. 1893, 

 pp. 98, 99). — Experiments in this line described in the Annual Report 

 of the station for 1892 (E. S. R., 4, p. 87) were continued in 1893. The 

 average for 3 years' experiments on upper bench soil shows an increase 

 of over 22 per cent for fall application in addition to spring application 

 of water. 



Night vs. day irrigation, J. W. Sanborn {Utah Sta. Bpt. 1892, pp. 

 99-103). — This is an account of experiments in continuation of those 

 reported in Bulletin 21 of the station (E. S. R., 4, p. 824). The results 

 with wheat show that " there was practically no difference in the grain 

 return, but that an increase of nearly 20 per cent was made in straw 

 in favor of night irrigation." This is probably due, as already sug- 

 gested, "to the check given the vegetative processes by irrigation, by 

 reducing temperature, resulting, as often occurs, in an increased pro- 

 portion of grain to straw." The results obtained with grass were 

 exactly the reverse of those obtained with wheat. In order to ascer- 

 tain the cause of this difference observations were made on the tem- 

 perature of the air and the moisture content of the soil under the 

 different systems of irrigation, but the data thus obtained were not 

 sufficiently definite to admit of conclusions. 



Irrigation, L. Foster and C. A. Duncan (South Dakota Sta. Ept. lS9£,pp. 35, figs. 

 5).—K reprint of Bulletin 28 of the station (E. S. R., 3, p. 890). 



Sewage irrigation, H. S. Orme {Amer. Pert., 1 {1894), No. 5, pp. 27S-2S0).—Bevf- 

 age irrigation in foreign countries is referred to and the practice is recommended for 



