262 SOIL SCIENCE [Bot. Absts. 



NITRIFICATION 



1803. Greaves, J. E., and E. G. Carter. Action of some common soil amendments. 

 Soil Sci. 7: 121-160. 1919. — To tumblers each containing 100 g. of soil and 2 per cent of 

 dried blood, the chlorides, carbonates, and nitrates of sodium, potassium, calcium, magne- 

 sium, manganese, and iron, and tht sulfates of calcium, magnesium, manganese and iron, 

 were added singly in amounts which had been found to produce the maximum nitrification 

 and ammonification. After 21 days incubation the water-soluble phosphorus and the organic 

 phosphorus were determined. Many of the above salts increased the water soluble phos- 

 phorus, the organic phosphorus or both. The increased crop growth noted from the use of 

 the above soil amendments can be accounted for by the increase in available nitrogen or 

 phosphorus. — William J. Robbins. 



1804. Metge, G. [Rev. of: Kuhn, A. Uber die Impfung von GeLreide, Hackfriichten 

 und anderen Kulturpflanzen mit "U-Kulturen." (The inoculation of cereair., etc.) [Deitsch. 

 Landw. Presse 44:467-468. 1917.] Biedermann's Zentralbl. Agrikulturcnem 47:261-263. 

 1918. — The author claims that his product U Kulturen- (Universal-Kulturcn) gave favorable 

 results in field experiments. The product is a mixed culture intended for use on non-legu- 

 minous plants. — F. M. Schertz. 



1805. Volhard, J. [Rev. of: Arnd, Th. Uber die Entstehungsweise salpeter- und 

 salpetrigsaurer Salze in Moorboden. (The origin of potassium nitrate and nitric a.ii in moor 

 soils.) Landw. Jahrb. 51:297-328. 1917.] Biedermann's Zentralbl. Agrikulturc . .^ in. 47: 

 291-294. 191S. — The author reviews the works of Ritter in regard to the origin of nitrates in 

 soils. He made qualitative tests, before and after inoculation of sterilized soils, for NH 3 , 

 KNO3 and HNO3. Nitrates do not arise alone from chemical reactions in the soil but in 

 general nitroso- and nitro-bacteria give rise to them. The author emphasizes need of fur- 

 ther work on the activity of soil bacteria. — F. M. Schertz. 



1S06. Volhard, J. [Rev. of: Munter, F. Uber Sorption und Nitrifikation von Arnmon- 

 verbindungen bei Gegenwart von Zeolithen im Boden, sowie iiber Ammoniakbestimmungen 

 im Boden und uber zeolithartige Substanzen. (On the absorption and nitrification of ammonia 

 compounds in the soil when zeolite is present, also estimation of ammonia and zeolite sub- 

 stances in the soil.) [Landw. Versuchsst. 90: 147. 1917.] Biedermann's Zentralbl. Agri- 

 kulturcnem. 47:289-291. 1918.— Some authors ascribe the absorption of ammonia salts in 

 the soil to zeolite which was present only in small amounts. Experiments were conducted 

 by adding zeolite (1-2 per cent) to the soil. Nitrogen compounds were then added in the 

 form of corn meal or ammonium sulphate. Ammonification and nitrification in a sandy 

 soil with zeolite corresponded to that in a clay soil. Author also estimated the ammonia 

 present in the soils. By direct distillation of the soil, ammonia was not set free without 

 decomposing nitrogenous bodies in the soil. The greatest differences were found when dis- 

 tillation took place with magnesium oxide and potassium chloride. Absorption then must 

 be conditioned by other substances than zeolite. It was further shown that the differences 

 did not depend upon denitrification, for total nitrogen estimations showed that no nitrogen 

 was lost. The author also worked on zeolite and its related compounds. The capacity of 

 soils for combination with ammonia salts seems to be closely related to the colloidal state. — 

 F. M. Schertz. 



