919 



loss of uitrogeii ami at the same time caused a gradual <liiiiinutiou of 

 ammoniacal nitrogen (2(;.73, liO.Ol, and 19.59 per cent) and a slight 

 increase of nitric nitrogen (().4;>, 7.44, and 9.7!> per cent). 



In a coni]>lctc soil (sand, clay, and lime) an addition of lactate of 

 iron, equivalent to 1 gram of sulphate per kg. of soil, almost prevented 

 the loss of nitrogen (only O.U i)er cent), increased the ])roduction of 

 nitric nitrogen from 7.14 to L'2.;>4 per cent, and diminished that of 

 ammoniacal nitrogen from 18.57 to 3.57 per cent. 



The salts of iron in general injuriously attect the ferments which 

 destroy nitrogenous matter, but the organic salts seem to favor nitri- 

 fication. 



In a complete soil the addition of 2 grams of ferric oxide to 1 kg. of 

 soil reduced the losses of nitiogen from 31.63 to 21.43 i)er cent, 

 increased the production of nitric nitrogen from 7.14 to 19.(;9 per cent, 

 and reduced that of ammoniacal nitrogen from 18.57 to 10.71 per cent. 

 The oxide of iron does not hinder the decomposition of nitrogenous 

 matter, but modifies the eneigetic action of carbonate of lime and favors 

 nitrification by fixation of ammonia after the manner of clay, and by its 

 oxidizing properties. The sulphate of lime (5 grams ])er kg.) was more 

 favorable to nitrification than sidjthate of iron. In pure sand it 

 increased the production of nitric nitrogen from 1.43 to 11.43 per cent; 

 in sand and carbonate of lime from 5.1 to 13.07 per cent; in sand and 

 clay from 5.1 to 23.07 percent; and in sand, clay, and carbonate of lime 

 from 7.14 to 34.48 per cent. 



For the conservation of nitrogen suli)hate of lime was nuich more 

 effective than sulphate of iron in clay soils, equally effective in silico- 

 calcareous soils, but on acccmnt of its inferior solubility much less effect- 

 ive in soils of pure sand. 



The use of sulphate of iron will prove valuable for the fixation of 

 ammonia in rapidly decomposing material, such as fresh manure, urine, 

 liquid manure, and sewage, but in slowly decomposing organic manures, 

 comi)osts, etc., its value is questionable on account of its antiseptic 

 properties. 



Sulphate of iron may be emjdoyed with favorable results on dry 

 sandy soils deficient in clay, lime, and oxide of inm. On all others 

 gypsum may be applied more advantageously. 



The efficacy of plaster used on soils containing clay and carbonate of 

 lime is explained. The effects of this jtractice are a modifying of the 

 a<-tion of carbonate of lime on nitrogenous organic matter, the fixation 

 of ammonia by the clay and gy]>suni, a reduction of the loss of nitro- 

 gen, and regularity of nitrification. 



Effect of sulphate of iron in the soil on the yield of different 

 cereals, A.Mayer {■hnir.f.Landn'.^iO^pp.Hi-:^.^). — These studies were 

 made at the experiment station at Wageningen, Holland, in the summer 

 of 1891. Ten large zinc cylinders were each filled with about 35 pounds 

 of soil, and 5 seeds each of rye, wheat, barley, and oats were sown in 



