FEKTILIZEKS. 667 



vetch $19.(38, vetch §19.(54, and red clover $17.90. Three of these crops contained a 

 cons-iiderable proportion of their fertihzing value in the roots, viz, " the cow horn 

 turnip 42 per cent, the alfalfa 40 per cent, and the red clover 30 per cent. None of 

 the remaining 5, the soy bean, the cowpea, the vetch, the rape, and the crimson 

 clover, had more than 10 per cent of the total value in the roots. Of the 'nitrogen 

 gatherers' the alfalfa showed the highest relative value in the roots, while the red 

 clover was but a trifle lower. On the contrary the crimson clover had, at least in 

 this experiment, the lowest relative value in its roots, viz, 5 per cent. The pre- 

 ponderance in most cases was due chiefly to the greater weight of the tops, but due 

 also in a less degree to the higher percentage of nitrogen and potash usually found 

 in the tops. The potash was invariably richer in the tops, sometimes nearly three- 

 fold richer; the nitrogen was likewise richer with but one exception, the red clover. 

 The phosphoric; acid was nearly ecjually distributed, sometimes richer in the tops 

 and sometimes in the roots. The relative amount of dry matter in the tops and 

 roots, at least in the case of crimson clover, was variable both with the particular 

 field of clover and with the stage of growth; the percentage composition was likewise 

 subject to considerable fluctuation." 



It is the author's opinion in view of these facts that the relative fertilizing value of 

 the roots of plants is often overrated. "In many cases, at least, it is small, some- 

 times quite insignificant." The crops as a whole showed an average of only 4 per 

 cent of the total roots below a depth of 8 in. The value of the phosphoric acid fur- 

 nished by the crops was comparatively insignificant, the most important element 

 being the nitrogen. The highest potash value, $8.07 per acre, was found in rape, 

 being 32 per cent of the total value. The cow horn turnip furnished $7.14 worth of 

 potash and the rye and vetch $6.76 worth, this being in each case about 34 per cent 

 of the total value. The changes which the organic matter of green manures undergo 

 in the soil by which they are rendered available as plant food are discussed in detail, 

 and the great benefit due to improvement in physical condition by the use of such 

 manures is explained. 



On the management and effect of barnyard manure, Schneidewind {Oesterr. 

 Cliciii. Zt(j., 6 {1903), No. 18, p. 41~)- — This is a brief note on an address before the 

 International Congress of Applied Chemistry at Berlin in 1903, calling attention to 

 the fact that the most effective manure is made up of the fresh liquid portion com- 

 bined with the decomposed solid portion and litter. Such manure may be ol^tained 

 by the sei^arate storage of the solid and liquid manure, but this method is as a rule 

 impracticable. The use of sulphuric acid effectually prevents loss of nitrogen, but it 

 also interferes with the proper decomposition of the manure. All preservative mate- 

 rial, such as lime, gypsum, copper sulphate, etc., as well as the various acid salt prep- 

 arations which are found in the market, are useless. Peat and earth are the most 

 serviceable preservatives that can be used. 



Nitrate of soda containing' perchlorate and its effects on plant growth, 

 H. Pellet and (J. Fribourg {Ann. Sci. Agron., 2. str., 1902-3, II, No. 2, jjp. 199-225, 

 fig. 1). — In this paper, which was jiresented to the International Congress of Applied 

 Chemistry at Berlin in 1903, the authors give results of investigations by themselves 

 and others on this subject, especial attention being given to methods of chemical 

 examination of nitrate of soda containing perchlorates. 



It is sh(jwn that commercial nitrate of soda may contain considerable amounts of 

 perchlorates, the proportion varying from traces to 1.5 per cent. In some samples 

 the amount present runs as high as 3.2 per cent to 6 per cent of perchlorates calcu- 

 lated as potassium perchlorate. The injurious effects which have frequently been 

 observed as a result of applications of nitrate of soda have generally been attributed 

 to potassium perchlorate. The investigations of de Caluwe, however, have demon- 

 strated that sodium perchlorate in the proportion of 1 per cent is also injurious to 

 vegetation and that potassium perchlorate and chlorate are much less injurious than 

 sodium perchlorate. 



