﻿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 rotted, 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 34 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. 



