CULTURE OF MA'ZE 239 



greater than when cultivated one and a half inches deep. 

 Studies of root growth of maize made at the Illinois Station 

 indicate that fifty per cent more roots may be cut off at four 

 than at three inches deep. The evidence in favor of shallow 

 cultivation is even more conclusive, therefore, than the table 

 indicates. While the evidence seems to show that the breaking 

 of the roots while the plant is less than six inches high is not so 

 serious as at later periods of growth, and that plowing deep at 

 the first cultivation is not so injurious as at a later date, yet, on 

 the other hand, evidence does not indicate any special benefit 

 from such deep culture in the majority of cases. Doubt- 

 less something will depend upon the previous preparation of the 

 seed bed. If the seed bed has not been properly prepared 

 before planting, or if the land has become extremely compact 

 from heavy rains or otherwise, a deep cultivation while the 

 plants are quite small may prove beneficial, but the evidence 

 clearly indicates that in the majority of cases shallow cultiva- 

 tion at all times will give the best results, provided such culti- 

 vation is equally effective in eradicating weeds. In practice, 

 shallow cultivation has been found equally effective in destroy- 

 ing weeds, provided the weeds are not allowed to get too 

 large, in which case deeper cultivation sometimes becomes 

 necessary. 



313. Amount of Cultivation. — The injury from root pruning 

 has generally been greater than injury from deep cultivation. 

 This may be due to the cultivation having injured less roots or 

 to the beneficial influence due to stirring the soil. During five 

 years the Illinois Station^ cultivated a plat tvvo inches deep 

 and four inches deep, while on an adjacent plat the weeds were 

 removed by scraping the surface with a sharp hoe without 

 breaking the crust of earth. The average yield was, deep, sixty- 

 six bushels ; shallow, sevent}'-two ; none, sixty-eight bushels. 

 During two years on one plat where weeds were allowed to grow, 



I 111. Bui 31, p. 356. 



