FERTILIZERS. 761 



way the available nitrogen decreased in 2i months from 21.56 to 5.94 

 per cent. 



Pot experiments with these two manures on white mustard grown on 

 sandy loam soils showed that the fertilizing effect in case of the first 

 was very small, and in case of the second practically nil. 



Experiments on the fertilizing effect of barnyard manure and 

 of its different constituents, ^I. jMaercker {Jahrh. arfr. chem. Vers. 

 Stat. Halle, ls95, pp. ■11-')G). — Experiments on oats grown on sandy 

 loam and on white mustard grown on sandy soil in pots to determine 

 the influence of various kinds of dung upon the fertilizing effect of 

 the nitrogren of nitrate of soda and urine are reported in detail. The 

 results show that the dung contains microorganisms which rapidly 

 destroy nitric and other available forms of nitrogen, so that it often 

 happens that soils fertilized with such manure will produce less than 

 unfertilized soil. The action of different kinds of dung in this respect 

 is very variable. The reducing effect of horse dung was greatest and 

 of sheep dung the smallest of the different kinds tested. 



Experiments on white mustard in which nitrate of soda was applied 

 at the same time with horse dung and 2 and 4 weeks after show 

 that the reducing effect of the dung upon nitric nitrogen probably 

 reaches the minimum in about 5 weeks, although it does not entirely 

 disappear within 3 or 4 months. 



The action of the different constituents of barnyard manure 

 (urine, dung, and straw), alone and in mixtures, M. Maercker 

 {Jahrh. agr. chem. Vers. Stat. Halle, 1895, pp. 69-77). — Cattle dung and 

 urine and wheat straw sex)arately and combined were compared, in pot 

 experiments, with nitrate of soda and with no manure on oats, followed 

 by white mustard grown on a sandy loam soil and on white mustard 

 grown on a sandy soil. The data are tabulated and discussed at some 

 length. The results clearly indicate that the addition of straw reduces 

 the effectiveness of the manure, the injurious effect being greater the 

 larger the amount of straw added. The use of excessive amounts of 

 straw as litter is condemned on the ground that it not only lowers the 

 effectiveness of the nitrogen of the manure, but also iu juriously affects 

 that of the soil and of other nitrogenous fertilizers that may be applied 

 with it. 



Tests on oats on sandy soil iu 1894 and rye on loam in 1894-'95 led to 

 the conclusion that the after effect of the difficultly soluble nitrogen of 

 manure is comparatively very small. 



Experiments on the fertilizing effect of phosphoric acid and 

 nitrogen in peat and excrement mixture, and in poudrette, 

 M. Maercker, H. Steffek, et al. {Jahrh. a<jr. chem. Vers. Stat. Jlalh; 

 1895, pp. 5-8).— An account is given of 3 pot experiments with white 

 mustard on sandy soil with 3 samples of peat and excrement mixture, 

 1 of which was acidified, and 3 samples of poudrette. The results show 



