1919] SOILS — FERTILIZERS. 627 



The fertilizing value of activated sludge, G. Q. Nasmith and G. P. Mc- 

 Kay (Jour. Indus, and Engin. Chem., 10 (lOlS), No. 5, pp. SSD-S^-i, figs. 7; abs. 

 in Engin. and Contract., 50 (1918), No. 2, pp. 31, 32). — Experiments are reported 

 in which air-dried sludge was compared with air-dried stable manure as a fer- 

 tilizer for radishes, lettuce, beans, beets, late radishes, tomatoes, carrots, and 

 onions on a poor clay soil low in organic matter. Both sludge and manure 

 were added at the rate of 14.5 tons per acre. Under the rather limited condi- 

 tions of the experiment it was found that the activated sludge in general gave 

 much better results than the manure. 



" From the results obtained it seems to be true that crops such as let- 

 tuce, . . . beans, beets, or tomatoes, . . . can be stimulated into very heavy 

 growth by the use of activated sludge. The increase in the yield of onions is 

 also great. ... In the case of radishes, though the final weight was not 

 materially greater, the radishes matured much more rapidly. . . . The same 

 holds good of lettuce or beets, in which the growth was much more rapid than 

 it was with the other fertilizer tested." 



Government Guano Islands, W. R. Zeedeebekq (Union So. Africa Dept. Agr. 

 Rpt. 1917-18, pp. 149-153). — This report states that the Government Guano 

 Islands of the Union of South Africa yielded from all sources 6,965.5 tons of 

 guano in 1917. Data on distribution and use are given. The average chemical 

 composition of the guano disposed of during 1917 was nitrogen, 11.06 per cent; 

 water-soluble phosphoric oxid, 3.5 ; citrate soluble phosphoric oxid, 11.41 ; total 

 phosphoric oxid, 11.46; potash, 2,5; and lime, 11.62 per cent. 



The relative availability of nitrate nitrogen and commercial organic nitro- 

 gen in cylinder and field experiments, A. W. Blair (Amer. Pert., 51 (1919), No. 

 6, pp. 56, 57). —The results of 20 years' cylinder and field experiments at the 

 New Jersey Experiment Stations are reported on the relative availability of 

 nitrate nitrogen and nitrogen from organic sources. 



Two types of loam soil and a loam with varying admixtures of coarse white 

 sand were used. For all of these soils, except those containing 80 per cent or 

 more of sand, the nitrates gave better yields and showed a higher percentage 

 of nitrogen recovered in the crop than the organic materials such as dried 

 blood, fish, and tankage. " Under the most favorable conditions only a little 

 over 60 per cent of the applied nitrogen can be recovered in the crop. . . . 

 Under less favorable conditions, the percentage recovery is much lower, often 

 amounting to only one-third of the amount applied." In the cylinder experi- 

 ments only about 38 to 45 per cent of the applied organic nitrogen was recov- 

 ered. The average recovery of nitrate nitrogen in the field experiments was 

 37 per cent and of organic nitrogen 26.5 per cent. It is suggested that the 

 superiority of nitrate nitrogen is due to its immediate availability' See also 

 a previous note (E. S. R., 41, p. 22). 



The manufacture of ammonia for fertilizer salts, C. Bosch (Ztsclir. Elektro- 

 chem., 24 (1918), No. 23-21,, pp. 361-369) .—TMa is a review of work in Ger- 

 many during the year 1918 on the synthesis of ammonia, with special reference 

 to use as fertilizer material. 



Potassium ammonium nitrate, a new top-dressing for sugar beets, M. 

 Hoffmann (Deut. Zuckerindus., 43 (1918), pp. 149, 150; abs. in Ztsclir. Angeic. 

 Chem., SI (1918), No. 84, Ref., p. 313; Jour. Soc. Chem. Indus., 37 (1918), No. 

 23, p. 744 A). — Potassium ammonium nitrate, prepared from ammonium nitrate 

 and potassium chlorid, has been found to be easy to distribute over the land 

 and can be safely used as a top-dressing. It contains about 13 per cent of 

 nitrogen, 25 per cent of potash, and fronf 27 to 30 per cent of chlorin. It has 



