320 EXPERIMENT STATION RECOED. 



lH). 139-lJiJi). — From the results of experiments made in large casks, hi 1900. 

 the conclusion is drawn that green manures turned under in October on light, 

 sandy soils decompose so rapidly that during the course of a mild wet winter 

 half of the nitrogen has been removed in the drainage water by February and 

 March. It is therefore recommended that green manures should not be turned 

 luider on such soils very far in advance of the planting of the cr.op. 



Modern methods of promoting the rational fertilization of farm crops, 



E. Wein (JaJirh. Dcitl. JAnidir. (Icurlh. .'i iUlOl). \o. 1. pp. 26-.'//). — A general 

 discussion of this subject. 



Fertilizers, D. W. May (Porto Rico >S7a. Ciic. tl. Eiif/Ii.sh. uiid t^panish eds., 

 pp. 16). — The general principles underlying the use of natural manures and 

 commercial fertilizers with special reference to Porto Rican conditions are 

 explained, with more specific directions regarding the use of fertilizers on 

 cotton, tobacco, sugar cane, citrus fruits, and pineapples. 



Fertilizer experiments on peat soils continued for 16 years, H. von 

 Feilitzen iSvenxka Mosskiiltiirfdr. Tidskr.. 21 (1907), No. 2. BUaga, pp. 199, 

 212). — The experiments have been conducted at Tobo, Sweden, since 1891, on a 

 marsh soil (starrtorf) with clay subsoil, the former containing 3.41 to 4.75 per 

 cent lime, 2.23 to 2.8G per cent nitrogen, O.OH per cent potash, and 0.07 per cent 

 phosphoric acid (in extract). The fertilizers applied during the series were 

 mostly Thomas slag in varying amounts, with potash and nitrate. The results 

 show the beneficial effect of an annual fertilization with both phosphoric acid 

 and potash on the yield and quality of the hay crop for meadows (m good and 

 well-cared-for peat land, and that the land can be kept in grass for a long series 

 of years b.v this system. The trials also furnish evidence that a liberal ferti- 

 lization of phosphoric acid and potash pays especiall.v well on account of the 

 after-effect which can be observed from the same for many .vears afterwards. — 



F. W. WOLL. 



Fertilizer experiments with nitro^n in different forms and amounts, 

 Clausen (Dent. Landic. Prcssc. 3-i (1901), No. 30. pp. 2^8. 2Ji9, fjg. i).— Com- 

 parisons of nitrate of soda and sulphate of ammonia on moor, sand, and loam 

 soils are reported. 



The effect of ammoniacal and nitric nitrogen on the development of corn, 

 M. SoAVE (Ann. R. Accad. Agr. Torino, .',8 (1906) ; at>s. in Hta;:. Hper. Agr. Ital, 

 39 (1906), Nos. 10-12, pp. 1100-110.')). — Experiments in nutritive solutions and 

 in soils are reported which confirm the general belief that ammoniacal nitrogen 

 must be first transformed into nitric nitrogen before it can be assimilated by the 

 maize plant. 



Studies on the value of calcium cyanamid as a nitrogenous fertilizer, A. 

 MuNTZ f;nd P. Nottin (Ann. Inst. Nat. Agron., 2. ser., 6 (1907), No. 1, pp. lJi5- 

 183). — After a brief review of the more important literature relating to the 

 preparation and use of calcium cyanamid, the authors report the results of their 

 own laboratory and culture experiments with this material. 



The use of the Kjeldahl method for determining the nitrogen in calcium c.van- 

 amid is recommended, complete reduction being brought about in one-half 

 hour. Comparative tests of the rate of nitrification, by the Muntz and Girard 

 method, showed that the amount of nitrogen nitrified in 5 months was in the 

 case of ammonium sulphate 100 per cent, calcium cyanamid 88 per cent, dried 

 blood G6 per cent, and roasted leather 26 per cent. The low rate of nitrifica- 

 tion was due to the fact that the application of the cyanamid in the amounts 

 used in these experiments (10 and 20 times that used in practice) retarded nitri- 

 fication and even resulted in denitrification at the beginning. When applied in 

 normal amounts or in large amounts fractionally nitrification was apparently 



