SOILS FERTILIZERS. 717 



deterioration in milling quality which the wheat underwent when grown in 

 California was due to climatic rather than soil conditions. 



Maintenance of soil fertility: Plans and summary tables (Ohio Sta. Circ. 

 lOJi, PI). 20, dgms. 5). — This circular is one of the annual statements on this 

 subject (E. S. R., 21, p. 216) and brings the data for the experiments up to the 

 end of 1909. 



The fertility of the soil, A. D. Hall {Science, n. ser., 32 {1910), No. 820, 

 pp. 363-371; Sci. Amer. Sup., 70 {1910), No. 1819, pp. 3U, 315).— This is a 

 review of scientific investigations bearing on this subject, beginning with the 

 experiments of Van Helmont in the seventeenth century and closing with the 

 recent work of Russell and Hutchinson on the functions of protozoa in the 

 soil, the purpose being to show " the continuous thread which links the 

 traditional practices of agriculture with the most modern developments of 

 science." 



Infection experiments with nitragin, Westmann {Ztschr. Landw. Kammer 

 Schlcsicn, 13 {1909), No. IJ,, pp. J,10-J,16, figs. 6).— The results of infection 

 experiments carried on for many years with serradella, in which the seeds were 

 inoculated with nitragin cultures, showed a marked increase in yield of green 

 fodder from the inoculated plats over the uninoculated, amounting in some 

 instances to as much as 6()(t iier cent. 



A report on inoculation experiments, K. Bkux {Prakt. BJ. Pflanzcnhau u. 

 Schutz, n. ser., 7 {1909), No. 10, pp. 133-136, fig. 1; abs. in Centbl. Bakt. [etc.], 

 2. Abt., 27 {1910), No. 10-12, p. 2J6).— The results of inoculation experiments 

 with nitragin on clover, lupine, serradella, and beans showed a marked increase 

 in the yield of green fodder from inoculated plats over the yield from 

 uninoculated. 



On the cooperation of micro-org'anisms in the utilization of insoluble 

 phosphates of the soil by plants, S. de Grazia {Ann. R. Staz. Chim. Agr. Spcr. 

 Roma, 2. so:, 3 {1909), pp. 203-208). — Previously noted from another source 

 (E. S. R., 23, p. 20). 



On the part bacteria play in fertilizing operations, P. Ehrenberg {Jahrb. 

 Deut. Landw. GeselL, 24 {1909). No. .',, pp. 915-926).— The author discusses the 

 decomposition of solid and liquid stable manures by bacteria, both before and 

 after they are put on the field, the resulting losses and benefits, and the condi- 

 lions under which such processes occur. The part that bacteria play in making 

 available green manures, lime nitrogen, and phosphoric acid, and the processes 

 of nitrogen fixation in the soil by symbiotic bacteria, are also discussed. 



Field tests with plant foods, materials and results, H. A. Huston {Abs. in 

 Science, n. ser., 32 {1910), No. 823, p. .'/7^')- — This is an abstract of a paper pre- 

 sented at the San Francisco meeting of the American Chemical Society, which 

 discusses the results of fertilizer experiments on wheat by experiment stations 

 in the winter wheat section of the United States. It is stated that the results 

 of these tests indicate that the use of commercial fertilizers on winter wheat 

 is unprofitable and that this is apparently in conflict with practical experience. 



Green manuring {Landw. Ztschr. Rheinprovinz, 11 {1910), No. 28, pp. If23, 

 42'f). — This article discusses (1) the crops best suited to green manuring, (2) 

 the time to sow crops, and (3) the depth to plow. In general those plants rich 

 in nitrogen and making the most growth in a short time are best. Shallow 

 plowing as a rule is recommended. 



Poultry manures, their treatment and use, W. P. Brooks {Massachusetts 

 Sta. Circ. 22, pp. ff). — Recent analyses by the station of poultry manures of 

 different ages and treated in various ways are reported and methods of preser- 

 vation are discussed. 



