34 ° 
Journal of Agricultural Research 
Vol. VIII, No. 9 
In each manuring treatment two cropped plots received each of the 
following quantities of irrigation water: None, 5, 10, 20, 30, and 40 
inches. This gave 6 cropped plots for each irrigation treatment. 
Besides the cropped soils, 6 plots receiving no water, 4 with 40 inches, 
and 2 of each of the other irrigated, unmanured plots were left fallow. 
Each of the manured, fallow series contained 4 plots unirrigated and 4 
irrigated at the rate of 40 inches, together with one plot for each of the 
other moisture treatments each year. 
The plots were 7 feet wide and 24 feet long, with 4 feet of space between. 
Two rows of Dakota Sunshine com were planted on each of the cropped 
plots, and one row in the spaces between the plots to make the con¬ 
ditions more uniform. 
Except for the year 1912, when the weather prevented the usual 
preparation of the land, the plowing was done in the fall and the soil 
Manure 
Applied 
Water 
Applied 
Fig. 5. —Graph showing the soil moisture and nitrates on August 7, 1911, to a depth of 3 feet in cropped 
soil to which different quantities of water and manure had been added. 
left rough until spring, when the manure was added to the plots which 
received this treatment. Later, the manure (mixed horse and cow 
manure, fairly well rotted) was thoroughly disked or plowed into the 
land. 
The water was distributed from wooden flumes as follows: For plots 
receiving 5 inches, 2% inches each at the beginning of tasseling and at 
roasting-ear stage; plots receiving 10 inches, 5 inches at each of the 
above two stages; plots receiving 20 inches, 5 inches each when the 
plants were 12 inches high, at the beginning of tassel, at bloom, and at 
roasting-ear stage; plots receiving 30 inches, 5 inches each when plants 
were 12 inches high, 10 days later, at beginning of tassel, at bloom, at 
roasting-ear stage, and 10 days later; and plots receiving 40 inches, 
applications of 5 inches when plants were 12 inches high, and this 
amount each week thereafter until all water was added. The fallow 
plots were irrigated at the same time as the cropped. 
