232 



Bulletin 247. 



Table III. Nitrogen in Soil and Subsoil. 



Surface foot ] ^^[^^ 



Second foot \ ^'"^l^^ 

 ( Late . 



Third foot -; Early 



Influence of -weeds. (Experiment by Gates.) 



During the winter of 1904-5 and during the spring and summer of 

 1905, Gates conducted at Gornell University a variety of investigations 

 to determine what was the reason or reasons for the well known detri- 

 mental influence of weeds, especially when allowed to grow in an inter- 

 tilled crop. Attention is called to four of 13 plats on which maize was 

 raised during 1905. The soil was Dunkirk clay loam. During May and 

 August the rainfall was below normal ; during June and July above 

 normal, being during June double the normal precipitation. 



Maize was planted on May 29th. Plats i and 4 were cultivated 

 throughout the whole period of growth, viz., about once in ten days from 

 June 14 to August 22d. On June 14 plat 2 was cultivated when series 

 I was sown to rye, series II to millet and series III allowed to grow to 

 weeds without further cultivation. Plat 3 was cultivated June 14 and 

 again June 22, when each series was treated as plat 2. 



The conditions under which these three series were conducted make 

 it impossible to compare one series with another. It is only possible to 

 compare the plats of a series with each other. Below is given the average 

 per cent, of moisture taken at intervals between June 27 and August 25. 

 In series I and III five determinations were made on each plat ; on 

 series II four determinations : 



Table IV. Percentage of Moisture on Cultivated and "Weed" Plats. 



