WATER SOILS. 



295 



"It will be seen from this table that while the total yield of dry matter was much 

 larger in 1891 than in the other 2 years, the amoniitof water used was also relatively 

 higher, the 3 trials of 1891 and 1892 averaging 509.5 lbs. of w^ater for 1 lb. of dry mat- 

 ter, wliile the average for the 4 cases in 1894 is 593.2 lbs. of water to 1 of dry matter; 

 the general average of the 7 trials being 557.3 lbs. to 1.'' 



The results of all experitnents of this character made at the Wiscoiisin 

 Station are sammarized as follows : 



Amouni of ivater required for a pound of dry matter in different crops. 



Dent corn 

 Flint corn 

 Red clover 



Barlev 



Oats .' 



Field peas 

 Potatoes. . 



No. 



of 



trials 



Water used' -p 1 Acre-incbes 



P«f/?"°'l matted per j »f ivater per 

 of rtry ' ton ot dry 



matter. ^^^- matter. 



Potmdi. 

 309. 84 

 2:J3. 90 

 452. 80 

 392. 89 

 557. 34 

 477. 37 

 422. 70 



Poundx. 

 19, 515 

 25, 099 



9,613 

 10,819 

 10, 755 



8,017 

 12, 805 



Inches. 



2.64 

 2. 14 

 4.03 

 3.43 

 5.02 

 4.21 

 3.73 



"It must be understood in considering these results that they apply to trials made 

 under conditions where none of the water used could be lost by percolation, and 

 that in irrigating very open soils, more water would be required unless applied in 

 small (quantities at a time." 



Field experiments on the percolation of water as related to 

 irrigation, F. H. King ( WisconKin *SYa. Bpt. 18'J4, pp. 249-265^ Jig. 1). — 

 Observations Avere made on this point on tile drains covering au area 

 of about 5 acres, and measuring 7,022 ft. in length. 



"These tile are laid at a mean depth of about 4 ft. in a soil which consists of 6 

 to 8 in. of a medium clay loam at the surface, followed by 2.5 to 3 ft. of clay, and 

 below this a rather coarse sand in the itpper portion of which the tile are laid. In 

 [a portion of the system] the lines of tile are 33 ft. apart, but the laterals leading 

 into the main extending from [the silt well] to the lake have a greater distance." 



Water was forced up into this system of tiles through the outlet drain 

 of the system by means of a rotary pump, having a capacity of 100 gals. 

 per minute. 



In the first experiment water was pumped 33 hours during portions 

 of 4 consecutive days. 



"Systems of 4-inch auger holes were put down at varying distances from the lines 

 of tile and in different portions of the area under experiment in which the height of 

 the ground water could be determined by direct measurement. A second method 

 consisted in taking samples of soil in 1-foot sections to a depth of 4 ft. along lines 

 parallel with but at different distances from the drains and then determining the 

 amount of water these samples contained when taken before and after the close of 

 the experiment." 



It was found that it was possible with this small pump to force water 

 into the system of drains as fast as it would percolate. 



"Through the sampling of the soil it was learned that during the 8 days following 

 this first experiment, the outlet of the drain luiving been kept closed, the water con- 

 tent of the soil changed as indicated in the table below." 



