514 EXPERIMENT STATION RECORD. 



Soil erosion, C. T. Amks {Mississipiji Hta. Bui. 165 (WUf), pp. 3-12, figs. 7). — 

 Experiments at the Holly Springs substation farm on the prevention of soil 

 erosion are described. 



The soil is the so-called brown loam with white impervious clay and a 

 reddish soil resembling sandstone for subsoil. Small gullies were filled with 

 team and plow and drag scraper, or by dynamiting. The former method was 

 found to be the cheaper. When the gullies are much larger it is stated that 

 satisfactory results can be had by running tei'races about 75 yds. apart on 

 the hillsides, forming a system of ponds to catch the wash soil, and which are 

 joined together by drains to carry off the surplus water during rains. "To 

 prevent soil washing, anything that will hold the soil in place, such as a sod 

 of bermuda or lesiiedeza, is excellent ; any device that will control the running 

 water so as to make it move slowly is more or less helpful and satisfactory." 

 The system of terracing, in which by means of rows and embankments the 

 water is made to run more slowly, is considered the best system to use on clay 

 soils in the South where rainfall is heavy. 



The laying off and construction of terraces is also described. 



Description of a wire cag'e used for the protection of pot experiments, J. G. 

 LiPMAN KT AL. {Ncio Jersoj Stas. Bui. 269 U'Jl-'t), pp. 18-20, pi. 1; Rpt. 1913, 

 pp. 484-^86, pi. 1). — Details of the construction of this cage are given. 



The influence of bacteria supplied in manure on the decomposition of green 

 manure, J. G. Lipman et al. (jVeu? Jersey Stas. Bui. 268 {1914), PP- 22-25; 

 Rpt. 1913, pp. 41 4-411). — This is a continuation of experiments, the first five 

 years of which were summarized in the report of the station for 1912 (E. S. R., 

 30, p. 325). 



The results show that applications of from 1,000 to 4,000 lbs. per acre of 

 manure gave little or no increase on plants receiving leguminous (crimson 

 clover) green manures but produced quite different results on plats receiving 

 nonleguminous (lye) green manures. The results in the latter case confirmed 

 those of the previous experiments in showing that greater increases in every 

 case resulted from small applications of manure alone than could be accounted 

 for by the plant food supplied, thus tending to confirm the conclusion " that the 

 bacteria conveyed in small quantities of cow manure are instrumental in bring- 

 ing about a more rapid decomposition of the green manure crop, and thus make 

 available more nitrogen for the succeeding crop." 



Oxidation of mang'anous carbonate by microbes, M. W. Beijekinck {K. 

 Alcad. WctensclL. Amsterdam, Yersl. Wis en Natuurlc. Afdeel., 22 {1913-14), Pt- 

 1, pp. 415-420; also in ditto Proc. Sect. 8ci., 16 (1913-14), pt. 1, pp. 391-401; 

 ahs. in Chem. Al)s., 8 {1914), No. 12, p. 2211).— The results of tests show that 

 culture plates of agar containing about 1 per cent of manganese carbonate 

 develop brown spots when inoculated with garden soil, indicating the oxidation 

 of the manganese by bacteria or by some of the fungi i^resent in the soil. 

 Apparently very different species of fungi are capable of producing such oxida- 

 tion, but all of the species are among those commonly found in humus. 



Investigations into the nitrogen metabolism of soil, JI. H. Gbeen {Centhl. 

 BaJct. [etc.], 2. Aht., 41 {1914), No. 18-23, pp. 511-608; ahs. in Jour. Chem. Soe. 

 [London], 106 {1914), No. 623, I, pp. 1113, III4).— In a continuation and exten- 

 sion of work by Lohnis (E. S. R., 17, p. 104S) the author reports laboratory 

 experiments on ammonification, nitrification, nitrogen fixation, and cyanamid 

 decomposition in both soil and solution media carried out on samples of soil 

 taken at approximately monthly intervals throughout the year, with particular 

 reference to the influence of season and of soil cultivation. A slight seasonal 

 variation is shown. 



