534 EXPERIMENT STATION RECORD. 



WATER— SOILS. 



Influence of subsoiling on soil moisture, F. H. King (Wisconsin 

 Sta. Rpt. 1896, pp. 166-177, jig. 1). — Four experiments are reported. 

 In the first, October 22, 189f>, a plat of u medium clay loam shading 

 into sand at a depth of 3 or 4 ft.," 27 ft. wide and 142 ft. long, was 

 plowed to a depth of G in. and a strip 9 ft. wide through its center was 

 subsoiled, by spading to a depth of 18 in. 



Before plowing and on April 8, 1896, the soil remaining undisturbed 

 in the interim, samples of the soil were taken to a depth of 4 ft. at G 

 equally distant points along 3 lines 9 ft. apart, and the amount of 

 moisture the soil contained determined. There was found to be little 

 difference (0.34 lb. in columns of soil 1 ft. square and 4 ft. deep) in the 

 total amounts of water in the treated and untreated soils, but the sur- 

 face foot of the unsubsoiled area contained 1.94 lbs. more water per 

 cubic foot than that which had been subsoiled. Examinations of the 

 same soils at later dates, April 1G and May 5, showed "that the differ- 

 ences existing in the amount and distribution of water in the subsoiled 

 and not subsoiled plats became less each time the samples were 

 taken, so much so indeed, that on May 5 there was in reality very little 

 difference between them." 



In the second experiment the attempt was made to determine the 

 effect of subsoiling upon the water content of soil from which evapora- 

 tion was prevented. 



"The soil was completely removed from an area f> by 6 ft. to a depth of 8 in. and 

 the subsoil spaded to a depth of 13 in. more, and after this had been done the sur- 

 face soil was returned to its place. There was no attempt to firm the soil except to 

 smooth the surface by the weight of a man standing on a 12-inch plank after the soil 

 was all in place. 



"Samples of soil were now taken to a depth of 5 ft. in 1-foot sections and each 

 sample was a composite of 5. Samples were also taken from a similar closely adja- 

 cent area which had not been subsoiled. 



"The holes where the samples had been taken were then closed at the top with 

 wooden plugs and then water was slowly applied to the 2 surfaces until 254.41 lbs. 

 or 1.06 in. had been added. 



"To prevent all evaporation from the surfaces they were each covered with a zinc- 

 lined wooden tray turned down over them and the soil banked up around the edges. 

 This work was completed on June 11, and on June 15 the trays were removed and 

 samples of soil again taken to a depth of 5 ft." 



The results show that the subsoiled plat not only retained all of the 

 254 lbs. of water added, but acquired 14 lbs. additional through upward 

 and lateral capillarity during 4 days. The plat not subsoiled, on the 

 other hand, lost 126 lbs. of water in the same time, or nearly half of 

 that applied. 



The third experiment was a repetition of the second, except that no 

 water was applied. The results show little change in the water con- 

 tent of the subsoiled plat. In the plat not subsoiled moisture accumu- 

 lated in the upper 3 ft., while the fourth and fifth feet became drier. 



