FIELD CROPS. 223 



Photochemical studies on the assimilation of nitrites and nitrates, O. 

 Baudisch and E. Mayer (Hoppe-Seyler's Ztschr. Physiol. CJiem., 89 {1914), 

 No. 3, pp. 175-227; ahs. in Jour. Chem. Soc. [London], 106 (1914), No. 617, I, 

 p. 365). — The authors claim to have shown that under suitable IHumiuation 

 both nitrates and nitrites give off oxygen, this result being due mainly to the 

 ultraviolet rays. In solutions of potassium nitrite in alcohol or aldehyde the 

 corresponding hydroxamic acids are produced. On prolonged illumination 

 amino-compounds, and probably nitrogenous cyclo-compounds, are formed after 

 the disappearance of the nitrite and the hydroxamic acid. This is said to be 

 the first instance of the conversion of nitrites and nitrates into organic nitro- 

 gen compounds by the action of light. It is thought probable that in plants the 

 same process may take place since here the factors nitrates, formaldehyde, and 

 light are present. 



An extensive bibliography is appended. 



The influence of salt on plants, A. J. Ewart {Jour. Dept. Agr. Victoria, 

 12 {1914), No. 7, pp. 420-423). — Experiments were carried out in 1912 and 1913 

 primarily to determine the after-effect of a salt dressing and how long the 

 effect lasts. Figures are given for eight common crops. 



A very heavy salt dressing retarded germination, the seeds in some cases rot- 

 ting in the soil. The injurious action of salt where it appeared is said to have 

 been due mainly to osmotic influence, the seedlings usually growing vigorously 

 after heavy rains began. 



The second year insufficient salt remained to injure the crops directly, and 

 a decided increase occurred in most of the crops tested. The stimulating action 

 of a moderate dressing of salt is said to be due partly to its solvent action on 

 the mineral constituents of the soil, possibly in part because the absorbed salt 

 acts as an oxidase sensitizer or catalytic agent in plant metabolism. The 

 injurious effect of a dressing of 64 cwt. of salt per acre was still perceptible 

 the second year after a rainfall of 35 in. with some crops noted, but a degree 

 of benefit was apparent in about as many others. One plat treated with 64 

 cwt. of salt and giving a high yield of beets in the first year gave a light 

 crop of rape the last year. It is thought that salt may increase the yield at 

 the expense of food materials in the soil, which thereby tend to be exhausted 

 by the increase of solubility of such constituents. 



The measurement of antagonism, W. J. Y. Osterhout (Bot. Gaz., 58 {1914), 

 No. 3, pp. 272-276, figs. 3). — Methods are suggested for the graphical expression 

 of antagonism in mixtures of three or more components in the nutritive medium. 



FIELD CROPS. 



The work of the Scottsbluff reclamation project experiment farm in 1913, 

 F. Knorb {U. 8. Dept. Agr., Bur. Plant Indus., Worlc Scottsbluff Expt. Farm, 

 1913, pp. 1-18, figs. 4). — In this paper the progress of the work with irrigated 

 crops in 1913 at the Scottsbluff experiment farm near Mitchell. Nebr., is briefly 

 discussed. The weather and crop conditions for the year are given. 



The crops used in the rotation experiments include alfalfa, beets, corn, flax, 

 oats, potatoes, and spring and winter wheats. These are arranged in 22 dif- 

 ferent rotations. It is noted that " in every case where the crops followed 

 alfalfa the highest average yields were obtained, indicating very strongly that 

 the alfalfa had a beneficial effect on the succeeding crops. Manure on oats 

 stubble greatly increased the yields of beets and potatoes the following year. 

 The yields of the crops following beets and potatoes were very good, almost as 

 good as those obtained with -crops following alfalfa or grown on manured oat 



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