120 EXPERIMENT STATION RECORD. 



from the experimental plats at the university farm. The results of the tests 

 on the small plats are in accord with tlie held tests in different parts of the 

 State. 



" Where clover was grown, crops rotated, live stock kept, and farm manure 

 used, an equilibrium as to the nitrogen content of the soil was maintained, the 

 mineral plant food was kept in the most availa))le condition and maximum 

 jields were secured." 



The nitrogen enrichment of soils through the growth of legumes, F. T. 

 Shutt {Caiiada E,ri)t. Farms Rpts, UK)'), iq). 127-13(1). — The cxliaustion of soil 

 nitrogen by continuous cropping withovit manure is illustrated l)y analyses of 

 virgin and cultivated soils of the Northwest Territories, and pot and plat ex- 

 periments extending over two years are reported which show that when mam- 

 moth red clover was grown on soils and turned under there was a gain during 

 the two years of 179 lbs. of nitrogen per acre to a depth of '.> in. in the pot 

 experiments and 17.") lbs. to a depth of 4 in. in the plat experiments. 



Inoculation for the growth of legumes, F. T. Shutt {Canada Expt. Farms 

 Rpts. 190.'), pp. 130-132, pi. 1). — Pot and plat tests of pure cultures furnished by 

 the Bureau of Plant Industry of this Department and the Ontario Agricultural 

 College on clover and alfalfa are reported. 



Comparisons were made of no treatment, inoculating seed, and inoculating 

 soil in the pot experiments and of untreated and treated seed only in the plat 

 experiments. In the pot experiments there was some increase, especially in 

 case of soil inoculation, the Ontario Agricultural College culture being more 

 efficient than the Bureau of Plant Industry cultures. In the plat experiments 

 on clover inoculation of the seed increased the yield decidedly, the Washington 

 culture being more effective than the Ontario culture. The results of the plat 

 experiments with alfalfa were inconclusive. 



The influence of charlock on nitrification in soils, E. Gutzeit (Ccnthl. Balct. 

 [efc], 2. Aht., 16 (1!>06), Ao. 10-13. pp. 3:^S-3S1 : ahs. in Jour. Chcm. Soc. [Lon- 

 don], 90 {190(S), No. .525, II, p. 476). — Field experiments and bacteriological 

 studies are reported which show that charlock may be prevented from producing 

 seed by one sprinkling with a 15 per cent solution of iron sulphate, and that the 

 injurious effect of the growth of such weeds on cultivated plants is due not only 

 to their draft upon the plant food, moistures, etc., of the soil needed by the cul- 

 tivated plant, but also to their influence upon the bacterial life of the soil, 

 especially upon nitrification, whicii is checked by the draft of the weeds upon 

 the lime and water content of the soil. 



Bacteriological methods, using nutrient solutions inoculated with soils and 

 also soil extracts as culture media, were found useful means of stud.ving such 

 questions. 



On methods of bacteriological investigation of soils, Buhleet and Ficken- 

 DEY (Genthl. Bald, [etc.], 2. Aht., 16 (1906), \o. 1(1-13, pp. 399-.',05; ahs. in 

 Jour. Chcm. Hoc. \Lo)i<lon], 90 {1906), No. 525, II, p. '/76").— A modification of 

 Remy's method of bacteriological examination of soils (inoculation of a definite 

 culture medium witli a fixed amount of soil shaken up in water) was used in the 

 study of the inlluence of aeration on the decomposition of peptone, denjtrifica- 

 tion, nitrogen assimilation, and nitrification in sandj', loam, hunuis, calcareous, 

 and garden soils. The results show that aeration reduced fornnition of am- 

 monia from peptone, increased denitrification and nitrogen assimilation, and de- 

 creased nitrification except in case of the hunuis soil. 



Green manures, F. B. Cruz {Estac. Cent. At/ron. Cuba Bui. .7, 2)p- 3S, pis. 5). — 

 A compilation of information on this sul).iect, adapted especially to Cuban con- 

 ditions and confined largely to a discussion of the usefulness of cowpeas and 

 velvet beans for this purpose. 



