FERTILIZERS. 21 



are reported in humus derived from black humus soil and sandy and loam black 

 soils. The percentage of total nitrogen in the humus varied from 2.74 to 4.59, from 

 one-half to two-thirds of the nitrogen being in form of amido acids, a few hundredths 

 per cent in form of ammonia, and the rest as amids. 



Humus and soil fertility, II. Snyder {Proc. Sue. Prom. Arjr. Sci. 1901, j)p. 

 62-65). — The value of humus for conserving moisture in the soil is discussed, and 

 data for determinations of moisture at different dates on soils containing varying 

 amounts of humus are reixjrted. These show that " whenever the moisture content 

 of the soil reached a comparatively low jioint the plat which contained the larger 

 amount of humus and upon which the crops had been rotated always showed a higher 

 per cent of water than the plat which had been under continuous wheat cultivation." 



The chemical role of earthworms, H. d'Anchald {Jour. Agr. Prat., n. ser., 3 

 {1903), No. '22, pp. 700, 701). — This is a summary of investigations by Dusserre,^ 

 which show that the excreta of earthworms contains more ammoniacal and nitric 

 nitrogen and undergoes nitrification more rapidly than the original soil, that solu- 

 bility of the phosphoric acid is increased in the soil by passing through the worms 

 while that of the potash is not affected, and that there is a larger jjercentage of car- 

 bonate of lime in the excreta than in the soil. 



The Campbell method of soil culture, H. M. Cottrell {Industrialist, 28 {1902), 

 No. 25, pp. 375-384, figs. 4). — The results of several years' tests of this method on 

 the station grounds and on a farm in western Kansas are said to show it to be an 

 effective means of conserving moisture in the soil in times of drought. 



Interior land changes {Queensland Agr. Jour., 10 {1902), No. 4, pp. 277-282, 

 figs. 5). — An account is given of the changes which have been brought about in vari- 

 ous parts of Australia by the shifting of sands during windy seasons. Various sand 

 dunes are described, and for the prevention of their encroachment the author recom- 

 mends the planting of wind-Iireaks wherever possible and the binding of the sands 

 by planting various plants which are adapted to growth in such regions. 



FERTILIZERS. 



Organic nitrogen availability of fertilizing materials, C. H. Jones and B. O. 

 White ( ]'ermont Sta. Rpt. 1901, jyp. 219-221). — Determinations by the alkaline- 

 permanganate method of availability of nitrogen in 61 samples of organic nitrogenous 

 materials obtained from various sources are reported. The results confirm those of 

 previous experiments (E. S. R., 12, p. 224) in showing "that the method is capable 

 of making sharp and true distinctions between most nitrogenous materials used for 

 fertilizing purposes, classifying them as good, medium, or poor. The chief material 

 to which the method does injustice is cotton-seed meal, which has a recognized high 

 availability, but which this treatment places in the medium to poor class. This 

 eccentricity is due to the relatively large amount of nonnitrogenous organic matter 

 contained in the cotton seed." It is recommended that fertilizers showing an avail- 

 ability of less than 50 per cent by this method be treated by the pepsin digestion 

 process, "which does full justice to cotton-seed meal." 



Observations on the number and depth of distribution of the roots of differ- 

 ent plants under various systems of manuring the soil, C. von Seelhokst 

 {Jour. iMndu'., 50 {1902), No. 1, p)P- 91-104). — From the results of a number of 

 experiments which are here reported the conclusion is drawn that plants when lib- 

 erally fertilized not only have a larger root system, but these roots descend deeper 

 into the soil, and are thus able to better withstand drought. 



Manure from steers and swine, W. A. Henry {Breeders^ Gaz., 41 {1902), No. 8, 

 pp. 367, 368). — The percentage of nitrogen and ash voided as excrement or secured 

 as animal produce with different farm animals is tabulated. 



' Ami. Agr. Suisse, 1902, No. 2. 



