624 EXPEEIMENT STATION RECORD. [Vol.36 



tin (E. S. R., 31, p. 722) "that green crops instead of being plowed or buried 

 by other methods directly in the soil on which they had been grown, should 

 first be treated in such a way as to bring them into a more suitable condition 

 for use as manure." Tests were made of methods of doing this with sann hemp 

 as follows: "(1) Aerobic, in which the green manure was fermented in heaps, 

 kept moist but not covered with clay, [and] (2) anaerobic, in which the heaps 

 were plastered with clay. The sann hemp was first cut into short lengths and 

 soaked in water in a pit for 24 hours. It was then removed from the pit and 

 transferred to anoth<?r shallow one, in this case about 1 ft. deep and 8 ft. 

 square." 



In aerobic fermentation " the soaked material was arranged in alternate 

 layers of sann and soil, the former about 3 in. and the latter about 0.5 in. in 

 thickness. The whole heap was then covered with a layer of soil about 3 in. 

 thick and finally with one of straw to prevent evaporation. Watering was car- 

 ried out about once a week, sufficient water being added to keep the top layer 

 moist. [In] anaerobic fermentation the heaps were arranged in the same 

 way, but each layer was consolidated by treading down, and the whole heap 

 was finally plastered with clay about 1 in. thick." After 48 days the heaps 

 were broken down and the material applied to experimental plats of tobacco 

 either in furrows or ridges. The results radicated a decided superiority of the 

 aerobically fermented manure applied in the furrows. 



" With regard to the difference in character of the anaerobic and aerobic 

 preparations, it was found that when first taken from the heap the former 

 contained no nitrate but a considerable amount of ammonia (recoverable by 

 distillation with magnesia although not free). A water extract of the material 

 was toxic to seedlings, but this condition was changed and nitrate formation 

 took place after aerobic couditions were introduced, more complete nitrification 

 of the organic nitrogen present being eventually obtained than was the case 

 with the aerobically prepared material. This was in accordance with the 

 laboratory observations of the previous year, and confirms the conclusion as 

 to the possibility of preparing a more rapid acting manure by this method, 

 keeping in view, however, the necessity for interposing an aerobic stage be- 

 tween the anaerobic preliminary one and the final application to the soil, not 

 only to promote nitrification, but to insure the oxidation and destruction of the 

 toxins produced." 



A note by S. Milligan especially on the economic feasibility of the proposed 

 method is included. 



Peat in 1915, J. S. Tubp (U. S. Geol. Survey, Mineral Resources of the 

 United States Calendar Tear 1915, pt. 2, pp. 1027-1030) .—This report deals 

 with the production and use of peat in the United States during 1915. 



" The production of peat for fertilizer and fertilizer filler during 1915 was 

 38,804 short tons, valued at $258,447, as compared with 37,729 short tons, valued 

 at $249,899, in 1914. . . . The lowest price per ton reported was $3, the highest 

 $16 and the average $6.75." The entire importation of peat litter in 1915 was 

 7,514 short tons, valued at $48,142. 



Some sources of potassium, C. T. Hirst and E. G. Cakteb {Utah Sta. Circ. 

 22 {1916), pp. S-12). — This circular deals briefly with the function of potash 

 In plant nutrition, the German potash deposits, and the consumption of potash 

 In the United States, but discusses more particularly the actual and possible 

 sourcea of potash In the United States, including especially alunite, leucite, 

 material from nitrate deposits near Rigby, Idaho, material from the bed of an 

 old alkali lake, and the ash of various desert plants. Analyses of the material 

 from the nitrate deposit, the lake bed, and of the ash of the desert plants are 



