Increase of Corn Crop by Irrigation 177 



Just before beginning the experiments it had been in clover, and 

 was dressed with farmyard manure at the rate of 44 loads per acre 

 before plowing, in the spring of 1894. Since this time it had re- 

 ceived no manure or fertilizers of any kind, one object of the 

 experiment being to ascertain whether under irrigation the land 

 rapidly deteriorates in productiveness. 



Each season the corn has been planted very close, in rows 30 

 inches apart and in hills 15 inches in the row, working upon the 

 hypothesis that when an abundance of water is supplied more 

 plants may be grown upon the same area, the hypothesis having 

 been suggested by the large yields universally secured in the 

 experimental cylinders. 



The number of stalks in a hill has varied, but usually as 

 many as 3 to 5 stalks have been allowed to mature. Both flint 

 and Pride of the North dent corn have been grown each year, 

 and one season a part of the area was planted with rows 36 

 instead of 30 inches apart. The table which follows gives the 

 yields of water-free matter per acre, together with the rainfall of 

 the growing season and water added by irrigation: 



Not Irrigated 



Irrigated 



Difference 



It will be seen, from the data of this table, that there has been 

 during the four years a mean gain due to the increased water sup- 

 ply amounting to 3,543 pounds of water-free substance, while the 

 mean yield under the season's rainfall with the best of tillage has 

 been 6,393 pounds per acre, or an increase of 55 per cent. The 

 smallest mean gain realized in any year has been 24.9 per cent 

 and the largest 278 per cent. 



