AGRICULTURAL ENGINEERING. 



733 



The water was brought to the ditch by means of i)ai:inel lines of 

 tile laid 33 ft. apart, many of which tapped springs. 



Esrperiments in irrigation, F. H. King ( Wiscousin Sta. Rpt. 1S95, 

 pj). 237-2'):2,fi(js. S.) — These cxi)eriments are essentially a rei)etiti()n of 

 those recorded in the Annual Keport of the station for 1894 (E. S. K., 

 8, p. 295). Tliey " had for their jirimary object the ascertaining of the 

 possible increase of yield over that Avhich may result from the natural 

 rainfall of the season and locality." 



Surface and .subirrif/atioit of coni. — 



" Tlie comp;iri3oa was made ixpoa 2 areas, one of which covered a little more tliaii 

 1 acre of j^rouud, while the other was only one-fourth as large. . . . 



"The larger of the 2 experimental areas (D) was divided into 5 e(|ual i)lat8, each 

 of which bore upon one half dent and ou the other half flint corn. The center i)lat 

 of the 5 was subirrigated, the adjacent ones on either sido were surface irrigated, 

 while the remaining 2 plats, one adjacent to each of the surface-irrigated plats, w. re 

 allowed to develop under the conditions of natural rainfall. 



"lu the subirrigated plat the water was distributed through 3-inch drain tile, placed 

 18 in. below the surface in parallel rows 10 ft. apart, but connected by a continuous 

 line of tile extending past one end of each row. . . . 



"On the smaller plat (C) subirrigated corn was compare,] with that not irrigated, 

 the tile being 18 in. below the surface and only 5 ft. apart. Flint corn was grown 

 upon this iilat." 



The yields of dry matter in thecoru on theditferent plats during 1894 

 and 1895 are shown in the following table: 



)lel(l>i of dnj matter in corn ou uiiirruiated, auliirri(jated, and surface-irrigated 2>Iatn. 



"It will be seen that in all cases the yield from the irrigated land was much larger 

 than from that not irrigated, and that the surface-irrigated lands j ielded both years 

 much better than the subirrigated lands did. ... In 1891 the surface-irrigated 

 corn gave a yield more than a third larger than tbat.not irrigated, while in 18i).") the 

 yield from the surface-irrigated ground was nearly i times that from tiie land not 

 irrigated."' 



The table shows that on the uiiirrigated soil the smaller the rainfall 

 the less the yield of corn, and that this was not due to the exhaustion 

 of the soil by the continuous growth of corn on the same land without 

 manuring is indicated by the fact that where surface irrigation was 



