13 



plowed, careful examinations were made and detailed notes were taken 

 regarding- the physical condition of the soil in each instance. It was 

 found that the Alfalfa sod was more difficult to plow than that of any 

 of the clovers or the grasses, but that the inverted sod of the Alfalfa plots 

 was exceedingly mellow and friable, surpassing all others in this par- 

 ticular. The comparative differences of the various sods can be under- 

 stood fairly well from the following figures : 



An Alfalfa sod is usually a little more difficult to plow than that of 

 some of the clovers and the grasses, owing to the very large roots of the 

 Alfalfa plants, which are frequently pulled out of the subsoil instead of 

 being broken or cut in two. When the roots, to the length of two, three, 

 four or five feet or even more, are pulled out of the subsoil and left in the 

 surface soil, a large amount of root material is thus deposited in the land 

 at the very surface. The land is thus left in excellent physical condition, 

 and as the roots decay they supply a large amount of humus, rich in fer- 

 tilizing elements. In 1898, the Experimental Department spent some time 

 in removing the Alfalfa roots from the land to a depth of two feet. This 

 was divided into four layers, and the roots were carefully separated from 

 each layer. The roots from each of these depths were then taken to the 

 Chemical Department, where they were analyzed. The percentages of the 

 fertilizing constituents in the dried roots of seventeen months' old Alfalfa 

 were as follows for each of four depths in the soil of six inches each : 



The roots of young Alfalfa plants were found to contain larger per- 

 centages of fertilizing materials than those of the plants which were 



