558 



In Xo. 9 tlie effects of di^ep and shallow cnltivntion were conipnred on 

 one piece of land; and on another piece the effects of prepaiiiiy the 

 seed bed at different depths were tested, the soil not being stirred after 

 the planting of the corn. 



The tract was scrapefl with sharp hoes to remove weeds with the least possil)! ^ dis- 

 tnrhnnce of tlie soil, three times between May 28 and June 27. 

 The yield of corn in bushels per acre was as follows : 



The effect of preparation of seed hed upon yield, 1890. 



Plat. 



Preparation of seed bed. 



Yield 

 per Hcrn. 



Not i)lnwefl 



Plowed '.i inclies deep. 

 Plowed 4 iiu'lii-s ileep. 

 Plowed 6 iuclios deep. 

 Plowed 8 inches deep. 



Bushels. 

 51). 4 

 59.9 

 6i). 4 

 e9. 3 

 71.7 



It is evident that on this soil good crops of corn may be raised with differently 

 prepared seed beds, without any stirring of the soil after the corn is planted, if the 

 weeds are thoroughly removed. 



In No. 10 the effects of root pruning 4 inches deep and 6 inches from 

 the hill at the second, third, and fourth cultivations were observed. 

 The results of the several experimeuts are stated in tables and are dis- 

 cussed in some detail. 



Experiment No. 54. — Corn, root groicth (pp. 423-428). — "As stated in 

 former bulletins, the particular object of inquiry in this experinu'nt was 

 to ascertain the number of the roots of corn and their depth at the 

 points where they were likely to be disturbed by cultivation, and what 

 proportion of all the roots was likely to be so injured." In 1890, fifteen 

 plants of Burr's White coru, containing 254 roots, were examined at dif- 

 ferent dates from May 24 to June 28, and the results are stated iu detail 

 in a table and briefly discussed. 



At the first week of examination, when the plants were from 1 to 2^ inches high, 

 there were three and four roots per plant. At the last examiuation, when the plants 

 were 62 to 05 inches high, they had thirty- five roots apiece. The longest root traced 

 was 53 inches, while another was found which was 51.5 inches loug. Three were 

 broken off at 50 inches or more, probably near their end. Twelve were traced 

 between 40 and 50 inches, some of which were broken at the lengths given. 



Two thirds of the roots would have been broken by root pruning \ inches deep; 

 more than two fifths would have been broken at 3 inches deep; and one seventh at 

 2 inches deep. 



In 1890, as in 1889, it was found that the depth of planting had little or nothing to 

 do with the depth at which the roots grew. The first whorl of roots, other than those 

 distinctly at the seed, which generally, if not always die, began to grow at from 1 

 to 2 inches from the surface of the soil, without reference to the depth at which the 

 seed was planted. The stem between the 8ee<l and the first nodal whorl of roots is 

 simply elongated and more slender if the seed is planted deeper. Nothing is gained, 

 therefore, by ]>lauting deeper than 2 or 3 inches iu this soil, unless the dryness of the 

 soil makes it essential. On the other hand, if it is necessary to plant deeper on 

 account of the dryness of the soil, or to plant some of the coru deeper where planting 



