842 EXPERIMENT STATION RECORD. 



The nitrifying' ability of normal soils and the loss of nitrates by leaching, 

 A. V. Klyucharev {Izv. Moscow Selsk. Khoz. Inst. {Ann. Inst. Agron. Muscou), 8 

 {1902), No. 2, pp. 107-U9).—ln continuation of previous work on the same subject 

 (E. S. R., 13, p. 535), the author undertook to investigate more fully and in greater 

 detail the phenomena which take place when soils are in contact with solutions of 

 nitrates. He foimd in experiments in cylinders containing from 2J- to 3h kg. of soil 

 that in case of soils containing a large amount of imperfectly decomposed organic 

 matter, or those to which starch was added, there was a marked denitrification, while 

 in soil in which humification was very advanced, like the chernozems, and to which 

 no stareli was added, there was little or no destruction of nitrates during 15 days. 

 These results indicate that the rate of denitrification is dependent largely upon the 

 amount of starch and similar compounds in the soil. It was shown in other experi- 

 ments that plant roots which are rich in pentosans also accelerate denitrification to 

 a marked degree. Chloroforming the soil prevented denitrification. Tlie results 

 further indicate that a considerable proportion of the nitrogen set free in the process 

 of denitrification goes in organic combinations — p. fireman. 



The crop and the soil in their mutual relations, S. Bogdanov {Selsk. Khoz. i 

 Lyesov., £05 {1902), Apr., pp. 51-90). — A review of a book by Bogoushevski entitled 

 Bad Crops and the Exhaustion of Lands — an Investigation of the Question of the Causes 

 of the Exhaustion of the Fertility of Soils, which minimizes the value of chemical 

 theory of the exhaustion of soils and gives prominence to the physical causes of tem- 

 porary unproductiveness due to improper management of the soil. The reviewer 

 maintains that the chemical and physical factors are of equal importance, and that 

 the use of fertilizers is an effective and necessary means of restoring and maintaining 

 the fertility of exhausted soils. — p. fireman. 



Practical experiments in the restoration of worn-out soils, R. F. Schwarz 

 {Pennsylvania Dept. Agr. Rpt. 1901, pt. 1, pp. 489-494).— K brief account is here given 

 of practical experience in restoring worn soils by means of leguminous plants — 

 crimson clover, cowpeas, vetches, etc. 



The purpose of a soil survey, ]M. "Whitxev ( f. S. Dept. Agr. Yearbook 1901, pp. 

 117-132). — This article discusses the knowledge of conditions necessary for agricul- 

 tural success, explains the deficiencies of older methods of soil investigation, and 

 describes the methods, purposes, and some of the results of the soil survey developed 

 in this Department. 



FERTILIZERS. 



The action of the solid constituents of stall manure, M. Gerlach {Jahresber. 

 Landw. Vers. Stat., Jersitz-hei-Posen, 1900-1901, p. 26; abs. in Centbl. Agr. Cliem., 31 

 {1902), No. 10, pp. 663-665). — Pot experiments comparing the fertilizing effect of 

 liquid manure and of manure which had been stirred up with 3 times its volume of 

 water and afterwards pressed are reported. It was found that the nitrogen of the 

 manure was in every case much less effective than that of nitrates, that the solid 

 constituents of the manure exerted an injurious effect, and that the action of nitrate 

 nitrogen was reduced when applied in connection with the pressed manure. 



A new method of conserving manure and urine, P. Rippert {Fuhling's 

 Landir. '/Ag., 51 {1902), Xos. 7, pp. 248-254, jig. 1; 8, pp. 278-285; 9, pp. 334-340).— 

 Laboratory experiments to test the value of different methods of meclianical treat- 

 ment and different kinds of preservative substances are reported. The results indi- 

 cate the importance of keeping manure compact, as in deep stalls, and show the 

 effectiveness of fluor-sulphuric acid, a by-product of superphosphate. manufacture 

 containing 10 to 12 per cent of free sulphuric acid and 20 per cent of fluorin, as a pre- 

 servative as compared with other preservatives frequently recommended — superphos- 

 phate-gypsum, sulphuric acid, etc. 



