1 2 ALPAIvFA 



and the alfalfa had yielded three crops. In the greater 

 portion of this trench it was necessary after removing 

 a spade's depth from the top to use a pick to loosen 

 the soil, which was so hard that the men ordinarily 

 did not at one blow drive the picks into it more than 

 two inches; yet, notwithstanding the hardness of this 

 clay soil, alfalfa roots had penetrated the depth of the 

 ditch, five and one-half feet in the deepest place, where 

 the roots appeared little smaller in diameter than they 

 were a foot below the surface (Figs. 5 and 6). 



When the alfalfa is once established, if there is 

 sufficient moisture to maintain the plant, it sends its 

 roots in quest of permanent moisture, and is only pre- 

 vented from reaching it by stone itself. The roots 

 have a strong and well-developed power of passing 

 around obstacles such as stones and boulders, and no 

 crevice is so small as to escape them in their downward 

 journeyings. Fig. 7 shows the development of alfalfa 

 roots in five months from seeding at the Kansas State 

 Agricultural College. The seeds were sown May ist, 

 and the photograph made October ist of the same 

 year. The growth shown was on high upland, seventy 

 feet to water, in a very old field never fertilized in any 

 way so far as known. The surface soil is black to 

 a depth of about twelve inches; below this and con- 

 tinuing as deep as excavated is a very stiff, hard, red 

 clay, full of small whitish stones. The top twelve 

 inches of the soil within the period of growth had been 

 wet by late rains, but the succeeding two and one-half 

 feet was so very hard and dry that it could not be 

 spaded at all. At five feet below the surface the soil 

 was moist, and the five and one-half feet of root which 

 penetrated the soil five feet — six inches being taken 



