BOTANY. 



517 



nary report is given on the root systems of wheat, oats, and corn, 

 with some discussion of the root systems of othcM- crops. The present 

 bulletin is devoted to investioations in the same line conducted in 1899, 

 and includes :i l)rief review of the study of the roots of wheat, oats, 

 and corn, and of the manner in which the root samples were prepared. 



A further investigation of the root system of flax showed that flax 

 possesses a very intricate S3^stem of rooting, and while the roots are 

 not as long, they more completelv occupy the upper layers of the soil 

 than the roots of wheat or oats. The roots of field peas were investi- 

 gated on plants 86 days after planting. The vines at this time were 

 5i ft. long, while the roots n^ached only to a depth of 3 ft. and were 

 rather sparingly supplied with branches and fibers. Like the roots of 

 the flax, the bulk of the fibrous roots lie within 8 or 10 in. of the sur- 

 face, showing that in practice peas do not requii'e a deep soil. 



The roots of 1 and 2 year-old plants of Bromux inermis were exam- 

 ined. At 1 year old the roots had attained a depth of over -l ft. and 

 formed a good sod. The roots of the 2-year-old grass were traced to 

 a depth of .5^ ft., and the author l)elieves they probably went a foot 

 deeper. Comparisons were drawn between the root systems of native 

 prairie grasses, timothy roots, and the roots of B ramus inermis, show- 

 ing that the native prairie grasses do not make as h^avy a sod as the 

 cultivated ones, the prairie-grass roots in the sample examined reach- 

 ing less than 3 ft. in depth. 



In the previous investigation the specimens of potato roots were 

 considered unreliable on account of the plants having been injured by 

 frost. In the investigations here reported, samples were taken of an 

 early and a late variety of potatoes, from which it was seen that the 

 main portion of the root growth is superficial. Forty-three days after 

 planting, the principal part of the root development was found to lie 

 within 8 in. of the surface of the ground. The lateral roots had 

 extended from hill to hill and interlaced. Some of the principal lat- 

 eral roots were found to be only 2i in. from the surface at 6 in. from 

 the hill. This root development would indicate the necessity of shal- 

 low cultivation of this crop, and this was confirmed in experiments with 

 deep and shallow cultivation, the results showing a decided advantage 

 for the shallow cultivation of potatoes unbilled. The samples of a late 

 variety of potatoes showed that late potatoes root more freelv and 

 more deeply than early ones, and as a result will not stand as close 

 planting as the early varieties. When the hills are a1)out 3 ft. apart 

 each way, the soil is very fully occupied by the roots to a depth of 3 ft. 



From examination of the roots of sugar beets it was found that this 

 crop does not develop lateral roots near the surface of the ground. 

 Tlie greatest amount of branching and fibrous growth of beet roots 

 takes place in the space between 8 and l-t in. in depth. 



The effect of subsoiling on root growth and development of sugar 



