THE IRRIGATION AGE. 



137 



is common that the plants are safe after they have put 

 forth their third leaf. 



In the colder portions of Montana, Wyoming, Col- 

 orado, Utah, and the Dakotas alfalfa is apparently winter- 

 killed from a variety of causes and sometimes from a 

 combination of causes. The percentage of loss around 

 Greeley, Colo., has been placed at 2 per cent per annum, 

 In this locality and throughout the Cache la Poudre val- 

 ley in northern Colorado most of the winter killing is done 

 in open, dry winters and is quite generally attributed to a 

 scarcity of moisture in the soil. In the winter of 1907 

 considerable damage was done to the alfalfa fields around 

 Loveland, Colo., on account of the long dry spell in mid- 

 winter. The old alfalfa fields suffered most. It was the 

 opinion of the farmers that a late fall irrigation would have 

 prevented the loss. 



Near Wheatland, Wyo., the higher portions of the 

 fields suffer most damage in winter, and here also the 

 cause is said to be lack of moisture in the soil, combined 

 with the effects produced by cold and wind. 



At Choteau, in northern Montana, a farmer watered. 



killing may be summed up as follows: Where both the 

 soil and the air are dry the plant should be supplied with 

 sufficient water for evaporation, but the land should be 

 drained so thoroughly that none of the top soil is satu- 

 rated; a late growth should not be forced by heavy irriga- 

 tions late in the growing season; if the soil is dry, irri- 

 gate after the plants have stopped growing; and the latest 

 growth should be permitted to remain on the ground, un- 

 pastured, as a protection. 



It may be stated in conclusion that the loss to the 

 farmer from the winter killing of alfalfa is not as great as 

 might appear at first. The damage is done in winter, and 

 there is ample time to plow the plants under and secure 

 another crop, which is usually heavy, owing to the amount 

 of fertilizers added by the roots of alfalfa. The Montana 

 farmer who increased his average yield of oats from 50 

 to 103 bushels per acre by plowing under winter killed 

 alfalfa illustrated this point. 



Seeding Alfalfa on Land to be Irrigated. 



In Utah the most common practice now is to sow 

 alfalfa without a nurse crop. From 12 to IS pounds of 



Tli 



e pumping plant shown above, located on the ranch of Sam J. McAfee, Ault, Colo., has been doing duty for four years. The 

 gasoline engine and centrifugal pump were sold and installed by Dempster Mill Mfg. Co., Beatrice, Neb. 



late in the fall, part of an alfalfa field which was two 

 years old, and it winter killed, while the unwatered portion 

 escaped injury. This and other evidence along the same 

 line which might be given go far to demonstrate that 

 under some conditions too much moisture is as detrimental 

 as too little. 



Probably the chief cause of the winter killing of alfalfa 

 is alternate freezing and thawing. The damage from this 

 cause is greatly increased when any water is left standing 

 on the surface. A blanket of snow is a protection, but 

 when a thin sheet of ice" forms over portions of a field 

 the result is usually fatal to plants. The bad effects of 

 alternate freezing and thawing on alfalfa may be observed 

 at the edge of a snow bank. This crop is likewise injured 

 by the rupture of the tap roots by the heaving of the soil. 

 From present knowledge of the subject, the means 

 which may be used to protect alfalfa fields from winter- 



Utah-grown seed is put in with a 6-inch press drill to a 

 depth of Y to 1J4 inches during the first half of April. 

 Irrigation before seeding is not necessary, as the soil 

 is usually moist and contain? sufficient moisture to sup- 

 port the plants until they attain a height of 6 to 10 inches. 

 At this stage the alfalfa and the weeds are cut about 

 4 inches above the surface, the cutter bar of the mower 

 being raised for that purpose, and the cuttings are left 

 on the ground. Water is kept off after cutting until the 

 crop begins to suffer. It is believed that when young 

 plants lack moisture they will strike their taproots deeper 

 into the soil in quest of water, and in this way develop a 

 better root system than they would under frequent and 

 copious irrigations. When alfalfa is sown with a nurse 

 crop, oats is preferred. From 10 to 15 pounds of alfalfa 

 seed is sown with 3 pecks to 1 bushel of oats. 

 (Concluded in August Number.) 



