50 FIELD AND GARDEN PRODUCTS 



clover and other leguminous crops in increasing the yields of the 

 succeeding crops. The roots add nitrogen directly to the soil and 

 are efficient by reason of their deep-feeding habit, bringing up other 

 mineral constituents from the lower layers of the soil and thus ren- 

 dering them accessible to the shallow-feeding crops. 



Results at the Wyoming Agricultural Experiment Station show 

 that on irrigated land the effect of alfalfa was to increase the value 

 per acre of subsequent crops as follows: Potatoes, $16; oats, $16; 

 wheat, $8 to $12. These increased gains were made without cost in 

 fertilizing the land, as the alfalfa had been regularly cut for hay for 

 five years. In Colorado and Nebraska the yields of grain are some- 

 times nearly doubled when immediately preceded by alfalfa. 



As an instance of the effect of alfalfa on soils in the South, it 

 may be mentioned that on a plantation near Shreveport, La., 23 

 bales of cotton, weighing 575 pounds each, were produced on 18 

 acres the season after an 11-year-old field of alfalfa had been plowed 

 up. This soil had been in cotton for several years previous to the 

 seeding of the alfalfa and had not given more than one-half bale 

 of cotton to the acre in any one season. 



Adaptability to Rotations. The value of a successful alfalfa 

 field is so great that there is always the temptation to let it stand as 

 long as it will produce paying crops. The difficulty of getting rid 

 of a stand of alfalfa, as well as the uncertainty of establishing the 

 new stand and the high price of the seed all work against the utiliza- 

 tion of alfalfa in the ordinary rotations of the farm. There are 

 many fields in the West more than 25 years old which are still giv- 

 ing satisfactory crops of hay. With the gradual exhaustion of soil 

 fertility, alfalfa is securing a place in the farm rotations in spite of 

 the drawbacks to its use in this manner. 



Getting Rid of Alfalfa. The methods adopted in eastern Col- 

 orado, where alfalfa is used to a great extent in short rotations, is to 

 plow shallow in the fall and then plow deep the following spring. 

 The plows are sometimes provided with a knife attachment to the 

 land side to cut the roots near the outer edge of the next furrow. A 

 riding plow is preferable owing to its rigidity. The fall plowing ex- 

 poses the crowns and a small portion of the root to the weather. The 

 deep plowing the following spring so effectualy buries the crowns 

 that the limited amount of reserve food present in the severed por- 

 tions does not enable them to reach the surface. The deep plowing 

 also prevents the cultivator teeth from catching on the alfalfa roots 

 when cultivating the succeeding crop. In some irrigated sections 

 it is the practice to flood the field to kill the plants before plowing. 

 In still other sections the stand is very heavily pastured, preferably 

 with hogs. This so reduces the vitality of the plants that it is com- 

 paratively easy to get rid of them. 



Alfalfa Varieties. Under most conditions, especially in the al- 

 falfa districts, ordinary alfalfa, whether from American or Euro- 

 pean grown seed, gives quite as satisfactory results as any of the 

 special varieties. In certain sections of the country, however, spe- 

 cial varieties of alfalfa have been found to be more valuable thaq. 



