208 SOIL SCIENCE [Box. Absts., Vol. X, 



1369. Elveden. a contribution to the investigation into the results of partial sterilization 

 of the soil by heat. Jour. Agric. Sci. 11: 197-210. 9 fig. 1921. — The effect of steaming soil 

 at 100°C. for 1 hour was studied. Samples of soil in 2-inch layers down to 18 inches were 

 used and crops grown over a period of 1-2 years, new series being set up every 3 weeks; data 

 were obtained at all seasons of the year. The soils varied considerably, some being field soils 

 which were much lower in organic material than others taken from gardens. Mustard was 

 used in all the experiments; crops were grown in boxes. Curves and tables are given show- 

 ing a considerable increase in yield for the steamed soils over those unsteamed, amounting in 

 1 series of garden soils to 603 per cent and in 1 of field soils to 403 per cent; the average increase 

 for the 44 experiments was 235 per cent. Steaming proved more eflBcacious in the richer 

 garden soils than in the poorer field soils. There was no indication that enemies of plants 

 congregate at a certain depth according to the season of the year. Soils below the point 

 previously disturbed by cultivation did not respond to the steaming. The benefit obtained 

 from steaming extends over more than 1 cropping period. Various other methods of steriliz- 

 ing soil — flaming and electrical heating — were not so efficient. To test out Russell's theory 

 of the action of soil protozoa, unsteamed soils were mixed with steamed soils in varying pro- 

 portions, the protozoan fauna being thereby supposedly quickly re-introduced. The results 

 all point to some other effect since the amount of yield varied rather directly with the amount 

 of treated soil present. The author concludes that the principal effect of steaming soils is a 

 direct one bn the composition of the soils rather than the destruction of protozoa. — V. H. 

 Young. 



1370. Fisher, R. A. Studies in crop variation I. An examination of the yield of dressed 

 grain from Broadbalk. Jour. Agric. Sci. 11: 107-135. 3 fig. 1921. — A survey is made of the 

 results of a statistical examination of the yield of plots of the Broadbalk wheat field at the 

 Rothamsted Station for a period of 67 years. The results are treated from a mathematical 

 point of view and an analysis made of the factors causing various types of variation over long 

 periods of time. The author finds that "average wheat yields, even over long periods from 

 different fields or for different seasons cannot approach in accuracy the comparison of plots of 

 the same field in the same seasons." — V. H. Young. 



1371. Fred, E. B. The fixation of atmospheric nitrogen by inoculated soybeans. Soil Sci. 

 11: 469-477. PI. 1-3. 1921. — On Plainfield sand, inoculation increased the yield of Ito San 

 soybeans more than 3 times and resulted in a net gain of 57 pounds of nitrogen per acre. Ap- 

 proximately 87 per cent of the total increase of nitrogen was in the soybean tops. Although 

 the latter were removed the favorable effect of inoculation was noted in the growth of rj'e the 

 following year. — W. J. Bobbins. 



1372. Fred, E. B., W. H. Wright, and W. C. Frazier. Field tests on the inoculation of 

 canning peas. Soil Sci. 11: 479^91. PI. 1-3. 1921. — Inoculation increased the yield and 

 per cent of nitrogen in canning peas on a rich, silt loam soil, unlimed and acid, and on a neutral 

 soil which had been heavily manured for several years. It had no effect on a slightly acid, 

 heavy, rich, clay loam soil. — W. J. Robbins. 



1373. Leach, B. R. Experiments with hot water in the treatment of balled earth about the 

 roots of plants for the control of Japanese beetle larvae. Soil Sci. 12:63-68. Ifig. 1921. — 

 Hot water, because of its slowness and injury to the trees, cannot be used to control the grubs 

 of the Japanese beetle. — W. J. Robbins. 



1374. Leach, B. R., and J. W. Thomas. Experiments in the treatment of balled earth 

 about the roots of coniferous plants for the control of Japanese beetle larvae. Soil Sci. 12: 43- 

 61. PI. 1-2. 1921. — The results of the toxicity of sodium sulphocarbonate, sodium ethyl 

 xanthate, sodium cyanide, copper sulphate, potassium fluoride, camphor, carbon disulfide, 

 thymol, mustard gas, and chloroform on naked Popillia grubs, on the grubs imbedded in soil, 

 and on the roots of coniferous trees are reported. — W. J. Robbins. 



