224 EXPERIMENT STATION RECORD. 



soils the largest yield was obtained with the iiiedimii percentage of water. In 

 similar experiments with llax on i)ealy clay the lowest yield was obtained with 

 the highest moisture content. With the other moisture contents the results 

 were variable and inconclusive. In experiments with tobacco on a sandy soil 

 the largest total yield was obtained with (50 per cent of moisture, the largest 

 relative yield of leaves with 40 per cent. White mustard on the same soil gave 

 the highest yield with the lowest peix-entage of moisture. Wheat on the same 

 kind of soil gave the highest yield with the medium percentage of moisture and 

 the smallest yield with the least moistiu'e. 



Ashes as fertilizer. — Straw ashes were used with good I'esults as a source of 

 potash in a series of experiments. 



CiiUurc on alkali soil from the Ural region.' — Experiments with sunun<'r 

 wheat on mixtures in varying proportions of pure clay soil and an alkali soil 

 are reported. The yield was not affected by the addition of 1 part of alkali 

 soil to 3 parts of clay soil. 



Report on veg'etation and laboratory experiments, 1904, 1906, and 1907, 

 I). N. Pkianisiinikov et al. {Iz Ueziilator \'< (/ctatzioiuuiikh Opiiitov I Luhont- 

 tonuiikh Eahot za WO.',, tDOG. i 1907. Moseoiv, 1909. pp. T7+2.37, pi. 1, figs. 65. 

 (Ignis. 6). — This is a collection of articles, dealing mainly with fei'tilizer experi- 

 ments, and noted from other sources (E. S. R.. 22, pp. 126. 127, 128, 129, 130, 

 20S. 222. 223. 224, 226, 228, 2.30). 



Experiments on the fertilizer requirements of soils, A. G. Doyabenko {Izv. 

 Moslcov. Selsk. Khoz. Inst. (Ann. Inst. Agron. Moscou), 15 {1909), No. 2, pp. 

 137-1-'/-'/). — Comparative tests of different fertilizers on clay and sandy soils in 

 pot and field experiments arc reported, showing that while the influence of the 

 different fertilizers was in the same direction in the pot and field experiments 

 the increase due to fertilizing were much greater in the former than in the 

 latter. 



Report of the chemist, P. L. GiLE (Porto Rico Sta. Bpt. 1908, pp. 29-32).— 

 A brief account is given of the work during 1908, which included mainly exami- 

 nations of soils and bat guanos, and studies of the decomposition of calcium 

 cyanamid in storage. 



Of the 23 samples of soils examined in a general way for acidity, lack of 

 humus, and similar unfavorable conditions, many were found to be decidedly 

 acid, and some were found to be unproductive on account of a strongly alkaline 

 condition. A stimulating effect on pineapples as a result of treatment of some 

 of the soils with carbon bisulphid is reported. 



Examinations of 16 samples of bat guano from caves in different parts of the 

 island showed nitrogen varying from 0.04 to 9.27 per cent, phosphoric acid 0.75 

 to 21.42 per cent, and potash 0.05 to 1.9 per cent. In the samples showing the 

 highest percentages of nitrogen this constituent was found to be largely in the 

 form of unavailable chitin derived from undecomposed wing and body coverings 

 of insects. 



Analyses are reported which show that thetuitii-ogen in calcium cyaHamid stored 

 in an open bin fell from 13.05 per cent, August 8, to 10.89 per cent, December 

 10. The nitrogen escaped largely, if not entirely, in the form of ammonia. 



An analysis of nitrate of soda, F. Schulze (Ztschr. Landw. Versuchsw. 

 Osterr., 12 (1909), Xo. 7, pp. 586, 587). — Samples taken from 3 different sacks 

 showed marked variation in nitrogen content. The average composition of the 

 mixed samples was nitrate of potash 7.69, nitrate of soda 36.93, magnesium 

 sulphate 17.79, sodium sulphate 0.66, sodium chlorid .30.31. sodium chlorate 0.61, 

 insoluble matter 1.11. and water 1.43 i)er cent. 



Precautions to be taken in employing' nitrate of soda as a top-dressing', 

 HiTiER (Engrais, 2-'/ (1909), No. 23, pp. 630, 631; ahs. in Chem. Ahs., 3 (J909). 



