AGRICULTURAL ENGINEERING. 



5!>5 



of the growing season (May 1 to August 3L) of 18)6, unlike that of 1894 

 and 1805, was not only fairly abundant (15,02 in.), but was generally 

 well distributed. "This being true, the irrigation experiments have 

 afforded excellent means for determining, under field conditions, how 

 much moisture is really needed in the soil to insure maximum yields." 



Experiments on potatoes, corn, clover, and cabbage are reported, 

 with estimates of the cost and profit of irrigation by pumping. 



Experiments with potatoes. — A plat of sandy clay loam, 87 by 287 ft., 

 after a liberal application of well-rotted barnyard manure, was planted 

 partly in Burbank potatoes, partly in Rural Xew Yorker potatoes. 



"Flat cultivation was adopted until July 8, when the potatoes were ridged for 

 irrigation. The whole plat of 115 rows was divided into alternating groups of 6 

 rows irrigated and not irrigated, separated hy 1 row of potatoes irrrigated only on 

 1 side. 



"The potatoes were irrigated on July 10, 21, August 3, 10, and September 3, 

 receiving each time 2.15 in. of water, or in the aggregate 10.75 in. more than the 

 rainfall." 



The following table gives the yields per acre of the 2 varieties: 

 Fields of potatoes on irrigated a ml unirrigated plats. 



Irrigated 



Not irrigated 



Rural Xew Yorker. 



Large. Small. Total. 



Burbank. 



Large. 



Small. 



Total. 



Bushels. Bushels. 

 382.0 12.2 



280.3 10.2 



Bushels. 



394.2 



. 290. 5 



Bushels. 

 220. 

 141.5 



Bushels. 



■1-1. 7 

 16.2 



Bushels. 



242. 7 

 157.7 



Determinations of the specific gravity indicated that the irrigated 

 potatoes were of as good quality as those grown on the unirrigated 

 plats. 



Experiments with corn. — This was a continuation of experiments of 

 previous years (E. S. R., 8, p. 733), except that subirrigation was not 

 practiced. The amount of water applied is not stated. 



"The yield of dry matter on the irrigated ground has exceeded that on the ground 

 not irrigated by about a ton to the acre, the average difference being 2,062 lbs., and 

 if this is figured as corn fodder couraiuing 15 per cent water it represents a gain of 

 1.213 tons per acre. 



"When the comparison is made on the basis of kiln-dried shelled corn the results 

 stand thus : 



Bushels. 



Dent corn, irrigated, thinned to 2 stalks. T 51. 2 



Dent corn, not irrigated, thinned to 2 stalks 42. 8 



Difference 8.4 



Flint corn, thick seeding, irrigated 51.9 



Flint com, thick seeding, not irrigated, 29.6 



1 Hfference 22. 3 



Experiments with clover. — Two crops of clover were cut on an area of 

 5.83 acres, the second growth being irrigated. Two plats were irrigated 

 June 18 and July 11, and two June 24 and July 13. All plats were 



