IRRIGATION AT UNIVERSITY FARM, DAVIS, CAL. 17 
gence of the irrigator along these lines is always going to be the con- 
trolling factor in success and failure or profit and loss. That the 
time of applying water is of as great importance as the quantity of 
water applied is shown plainly in 1910, in plat 1-C. where two irri- 
gations followed in close succession and the increase in yield due to 
the second irrigation did not pay for the cost of the irrigation. 
IRRIGATION AND CROP ROTATION EXPERIMENTS IN 1912. 
It was decided in the fall of 1911 to turn under a part of the 
alfalfa as green manure, and in the spring of 1912 to start a crop rota- 
tion of grain, sugar beets, corn, and potatoes, following alfalfa, these 
crops to be investigated from an irrigation standpoint, showing the 
increase in yield, with the increased amounts of water applied. Com- 
parison also was to be made with the returns obtained from the un- 
fertilized soils in previous years. 
Early in November. 1911. plats 1 to 15 and 32 to 37 were plowed to 
a depth of '8 inches with a two-gang plow. At this time the alfalfa 
had about a 6-inch top growth, and a good covering of green manure 
was turned under. Following this plowing the land was harrowed. 
cross-harrowed, and disked^ leaving it in a finely pulverized condition 
to receive the winter rains. 
On February 1. 1912. the land was replowed to a depth of 6 inches, 
harrowed, and cross-harrowed. Owing to the light winter rains the 
green manure had not thoroughly dotted, although the soil turned up 
in a fine, mellow condition, presenting the appearance of recently hav- 
ing been given a heavy application of rotted stable manure. 
Owing to the checking system of plats 1 to 15. it was necessary to 
relevel them for furrow irrigation. This area was later seeded to 
sugar'beets. Indian corn, and Egyptian corn. 
GRAIN FOLLOWING ALFALFA. 
Following the replowing and harrowing on February 1. the east 
halves of checks 32, 33. and 31 were seeded to 60-day oats. 75 pounds 
of seed per acre being planted. At the same time the west halves 
of these checks were seeded to Australian white wheat, at the 
rate of .85 pounds of seed per acre. All of the seed was drilled in. 
the drills running lengthwise with the checks, and a good stand came 
up on all of the checks. 
