198 MASS. EXPERIMENT STATION BULLETIN 280 



Field Experiments with Tobacco. (A. B. Beaumont and M. E. Snell). 

 Yields of tobacco in the field experiments were above average in 1931, but not 

 quite so good as in 1930. 



Cropping Systems. The highest yield (1816 pounds cured tobacco per acre) 

 was obtained from plots which received a full ration (3500 lbs.) of commercial 

 fertilizer (4.1%N, 4% PjOs? 5% KjO) and had a cover crop of redtop the previous 

 winter. Rye and timothy also, as cover crops, were beneficial but not to the same 

 degree as redtop. Three-fourths ration of commercial fertilizer supplemented by 

 10 tons manure produced more tobacco than fertilizer alone, and about the 

 same as a full ration of fertilizer with cover crops. A cover crop of timothy had 

 a slight depressing effect on the results from manure and fertilizer. Low yields 

 of tobacco were again obtained in the animal husbandry rotation (corn, timothy 

 or clover, and tobacco). The yield of tobacco in this rotation was somewhat 

 better after clover than after timothy, but following both crops only about 

 two-thirds that of tobacco grown in continuous culture. 



Different Quantities of Nitrogen. The highest yield (2025 lbs.) was obtained 

 with 205.6 pounds nitrogen per acre, followed by 1953 pounds tobacco from 

 164.5 pounds nitrogen, 1727 from 123.4 and 1513 from 61.7. These figures are 

 more in accordance with the mean of the past several years than were those of 

 last year. 



Different Carriers of Nitrogen. Where tobacco was preceded by timothy sod 

 two years ago, the largest yield was obtained with ammonium sulfate, followed 

 by sodium nitrate, cottonseed meal, and the standard mixture. Where timothy 

 sod immediately preceded tobacco, the order of production was urea, ammonium 

 sulfate, sodium nitrate, standard mixture, and cottonseed meal; but all these 

 yields were only about three-fourths those from plots having corresponding 

 treatments, but two years removed from timothy sod. L^rea was introduced in this 

 experiment for the first time this year and only on plots immediately following sod. 



Method of A pplying Fertilizer. A full ration applied in the row caused some 

 stunting of plants, but in the end produced more tobacco (1996 lbs.) than the 

 same amount applied broadcast (1906 lbs.); three-fourths ration in the row 

 produced slightly less (1883 lbs.) than the full ration broadcast (1906 lbs.); 

 and one-half ration in the row produced considerably less (1677 lbs.) than the 

 full ration broadcast (1991 lbs.). 



Miscellaneous. Milorganite, an organic fertilizer made from processed sew- 

 age, again proved a good substitute for cottonseed meal for tobacco, producing 

 1911 pounds cured tobacco. The quality of last year's crop from this material 

 was slightly below that from cottonseed meal. 



When ground tobacco stems were substituted for potassium salts as the car- 

 rier of potash in the standard fertilizer mixture, the yield of tobacco was 1459 

 pounds, while that from the standard mixture was 1689 pounds. 



Nitrogen Metabolism in the Tobacco Plant. (W. S. Eisenmenger.) 

 Tobacco plants grown in nutrient salt solutions were analyzed for total nitrogen 

 and for the following nitrogen fractions: ammonia, nitrates, alpha amino acids, 

 amides, water soluble albumen, proteose, and humin. Relativel}^ large amounts 

 of inorganic nitrogen were found in the plants. The plant parts arbitrarily chosen 

 for analysis were roots, stems, midvein of leaves, and the residual part of leaf 

 after midrib was removed. Although no categorical statement can be made as 

 to the exact location of reduction of nitrate nitrogen in the plant, inferential 

 evidence from the analyses would indicate that this process takes place at or 

 near the midvein of the leaf. 



