ANNUAL REPORT, 1934 11 



obtained from seedings of December, January, and February. Results were 

 progressively poorer from March to May. It appears that winter seeding of 

 sweet clover in this manner may be very practical, and either unhulled or hulled 

 seed may be sown. Some of the seedings were on the surface of deep snow. 



Field Experiments with Tobacco. (W. S. Eisenmenger, A. B. Beaumont, and 

 M. E. Snell.) 



Cropping Systems. The tobacco experiments reported in 1933 have been 

 continued. No lime was added to the soil during the past year, and the pH has 

 remained at approximately 5.0. The soil, in addition to lending itself to attack 

 of "brown root-rot" of tobacco, also contains Thielavia basicola (black root-rot 

 organism) in sufficient quantities to be harmful to the crop. 



The following are the yields that have resulted from different treatments under 



the same conditions of fertilization: 



Pounds per Acre 



Check plots without lime 1732 



Check plots with lime 1587 



Red top cover crop 1832 



Clover cover crop 1 666 



Spring wheat cover crop 1677 



Oats cover crop 1 690 



Barley cover crop 1737 



Manure (no cover) 1852 



Manure and red top cover crop 1786 



After clover hay (old animal husbandry plots) 1991 



After clover hay (new animal husbandry plots). 1699 



After timothy hay (old animal husbandry plots) 1217 



After timothy hay (new animal husbandry plots) 2014 



J Corn stover applied to tobacco soil plots 1755 



1 Check 1659 



f Corn stubble removed 1860 



j Check 1921 



(Corn soil treated with orthocresol 1772 



[Check 1553 



Form of Nitrogen. In this experiment, one-half the nitrogen applied in fertil- 

 izers comes from cottonseed meal and the other half from one of five nitrogenous 

 fertilizer materials. The experiment has now run three years. For the entire 

 period of the experiment the highest mean yield of tobacco has been produced 

 by the standard fertilizer mixture (nitrogen }/£ from cottonseed meal, 34 from 

 calurea, and 1/8 each from nitrate of soda and nitrate of potash), followed closely 

 by calcium cyanamide, nitrate of soda, sulfate of ammonia, and urea, in order. 

 The differences obtained thus far are hardly significant, although rather con- 

 sistently in the same direction. 



Proportion of Organic Nitrogen. In this experiment, which has run three years, 

 fertilizer mixtures containing different proportions of nitrogen from cottonseed 

 meal and inorganic sources are compared with each other and with the standard 

 mixture used in all experiments with tobacco at this station. In 1934 the highest 

 yield (2127 lbs. per acre) was obtained from the standard mixture (containing 

 Y2 organic nitrogen), followed very closely by that from the mixture contain- 

 ing 1/8 organic nitrogen and 7/8 inorganic nitrogen. For the period of the ex- 

 periment, the mixture containing 1/8 organic nitrogen has yielded the most 

 tobacco, but differences among yields from all mixtures have been small. The 



