March, 1920] SOIL SCIENCE 125 



849. Burgess, P. S. Can we predict probable fertility from soil biological data? Soil 

 Science 6: 449^101. 1918. — Nine Hawaiian surface soils which had been under sugar cane 

 cultivation for many years and which differed in fertility were tested for ammonification, 

 nitrification, total supplied organic nitrogen rendered water soluble and nitrogen fixation. 

 Incubation periods of 10, 20, and 30 days were used and dried blood, alfalfa meal, and fish 

 scrap were employed. With 2 per cent of the organic materials in 50 grams of soil, ammonia 

 production was generally greater in very good soils and less in very poor soils. Exceptions 

 are noted and the conclusion is drawn that ammonification tests are not suitable for deter- 

 mining the fertility of average Hawaiian soils. Using 30 mgm. of nitrogen as dried blood in 

 100 grams of soil and a 30-day incubation period at28°C, a good correlation was found between 

 the nitrates produced and the crop-producing power of the soil. A close correlation was also 

 found between the amounts of nitrogen fixed in mannite solution cultures and the known 

 fertility of the soils studied. — William J. Robbins. 



850. Conn, H. J., and J. W. Bright. Ammonification of manure in soil. Jour. Agric. 

 Res. 16: 313-350. 1919. — A foreword by Conn refers largely to previous studies of spore- 

 formers and non-spore-formers. Under the title, "What soil organisms take part in ammoni- 

 fication of manure?" Bright shows the predominance of Pseudomonas florescens and Pseudo- 

 monas caudatus in manured soil and gives the results of an investigation of their function in 

 Dunkirk silt clay loam. — Fresh horse or cow manure was added to the soil in the ratio of 1 : 20. 

 In addition to plate counts, direct microscopic examinations were made. Not only was the 

 unsterilized material used but also the sterilized to which was added the pure cultures. The 

 latter were used both separately and in combination. — In unsterilized soil which was kept 

 in pots the data show a rapid increase in non-spore-formers. After 7 days they were never 

 less than 92.5 per cent while in certain cases they were as high as 97 per cent. The results 

 from experiments conducted in flasks are not so striking yet the same relation holds. Isola- 

 tions showed only 2.8 per cent which form spores. — The growth of Ps. fluorescens and Ps. 

 caudal us in sterilized, manured soil compared with that of a spore former, Bacillus cereus, 

 shows that spore-former had increased in 7 days only 8.3 times while the two former organisms 

 had increased respectively 110 and 132 times over the original inoculation. 



851. Fisher, M. L. The washed l&nds of Indiana: a preliminary study. Indiana 

 (Purdue) Agric. Exp. Sta. Circ. 90. 24 p., fig. 1-lS. 1919— See Bot. Absts. 3, Entry 467. 



852. Gladwin, F. E. A test of commercial fertilizers for grapes. New York Agric. 

 Exp. Sta. [Geneva] Bull. 458: 27-43. 1919. 



853. Howard, L. B. Relation of lime requirements of soils to their retention of ammonia. 

 Soil Science 6: 405-411. 1918. — A method is described of determining the lime requirements 

 of soils by treating them with ammonium hydroxide. To 25 grams of soil in an evaporating 

 dish 50 cc. of 0.2 N ammonium hydroxide is added. The mixture is stirred occasionally during 

 a period of 1 hour. The solution is evaporated to dryness on a water bath. The soil is rubbed 

 up with a pestle and allowed to remain on the bath for If hours. The ammonia is then deter- 

 mined by the aeration method. Blank determinations are made on each soil. The lime 

 requirement found by the above method was about 25 per cent less than that found by the 

 Veitch method, and agreed in general with field observations regarding the need of lime by the 

 soils studied. — William J . Robbins. 



854. Johnson, James. The influence of heated soils on seed germination and plant growth. 

 Soil Science 7: 1-103. PI. 1-8. 1919. — Seven soils were subjected to dry or moist heat under 

 varying conditions and their action on various seeds and plants determined. On heating 

 soil to different temperatures it was usually found that the toxicity to seed germination and 

 to early plant growth increased to a maximum at approximately 250°C. and decreased to 

 practically nothing in soils heated to 350°C. or above. The growth of fungi on the heated 

 soil, ammonia content of the heated soil, and concentration of the soil solution were corre- 

 lated with the toxicity to seed germination. No correlation, however, was found between the 



