GRASS AND HAY 35 



exceeding 8,000 feet in Colorado. Under proper irrigation it yields 

 abundant crops in the deserts of Arizona, which are among the hot- 

 test in the world. The hardy strains are able to withstand the severe 

 winters of the North Central States. It is raised without irrigation in 

 semi-arid sections where the rainfall is only 14 inches a year, and also 

 in the Gulf States where the annual rainfall may amount to 65 

 inches. A rainfall of 36 inches a year is ample for this crop, and an 

 amount in excess of this is usually a detriment. In moist climates 

 the soil is frequently sour, and the clay soils especially are apt to be 

 too poorly drained. In such a climate weeds and fungous diseases 

 prove much more injurious than under less humid conditions. Al- 

 though the adaptability of alfalfa is great, yet in the areas not per- 

 fectly suited to its successful production care is necessary to provide 

 the very favorable conditions required by the young plants in order to 

 overcome the natural drawbacks. 



Soil. A deep, fertile, well-drained soil rich in lime and reason- 

 ably free from weeds is necessary for alfalfa. The lack of any of 

 these essentials is apt to be the cause of failure, especially in the East- 

 ern and the Southern States, where alfalfa is at best produced with 

 some difficulty. If the soil lacks depth the alfalfa plant is unable 

 to utilize its deep-feeding root system and is less likely to withstand 

 the inroads made by the surface-feeding weeds. The roots can, how- 

 ever, penetrate rather stiff clay soils, and even some of the soils under- 

 laid with hardpan. Instances have been observed in the limestone 

 sections of the Eastern and Southern States where alfalfa was grow- 

 ing successfully on soils underlaid at a depth of but 18 inches with 

 limestone ledges. It is able through the nodule-forming bacteria 

 within its roots to add nitrates to the soil and in this way increase 

 its fertility. Since large yields of alfalfa draw on the soil rather 

 Leavily for the other elements of fertility, it usually requires the 

 richest and best-drained soil the farm affords, and will bring returns 

 to justify the use of this land. There is risk, however, in selecting 

 bottom lands for alfalfa, on account of failure to drain and owing to 

 the danger from weeds. In the East it is usually best to develop the 

 fertility of some of the higher rolling land and seed this to alfalfa. 

 West of the Mississippi River the soils are usually fertile enough 

 for alfalfa without the use of any fertilizer. But even there the time 

 will come when some attention will have to be paid to fertilization, 

 as the best of soil will in time give way to the exactions of any crop. 

 In the East and South, however, they usually require some arti- 

 ficial treatment to bring them up to the proper degree of fertility 

 before alfalfa can be safely planted. This result may be brought 

 about by the plowing under of some green-manure crop, the applica- 

 tion of commercial fertilizers, or the spreading of barnyard manure. 

 Manure for Alfalfa. Well-rotted barnyard manure is usually the 

 most satisfactory fertilizer for alfalfa. Fresh manure is apt to carry 

 large numbers of weed seeds; therefore, if necessary to use it, the 

 application should be made to the preceding crop. This will give 

 lime for the germinating weed seeds to be destroyed by the cultiva- 

 tion of the preceding crop or by the stirring of the ground incident 



