270 SOIL SCIENCE [Box. Absts., Vol. IX, 



some Oregon soils do not respond to lime treatment, pure calcium carbonate or calcium oxide 

 was added to soils in pots and allowed to weather 1 year. A crop of barley was grown in the 

 pots. At the end of a year samples were removed from the pots and the forms into which the 

 calcium compounds had changed determined. The calcium was found chiefly combined with 

 humus and easily decomposable silicates. Most of the calcium present in the acid soil 

 which does not respond to lime was found combined as difficultly decomposable silicate. — 

 W. J. Robbins. 



GENERAL 



1662. Becklet, V. A. The formation of humus. Jour. Agric. Sci. 11: 69-77. 1921. 



1663. Colby, G. E. A note on the use of anhydrite as a remedy for black alkali. Monthly 

 Bull. Dept. Agric. California 10: 39-41. 1921. — Anhydrite was found to possess the same 

 value as gypsum or land plaster as a chemical remedy for black alkali. — E. L. Overholser. 



1664. Fred, E. B., and AtTDREY Davenport. The effect of organic nitrogenous compounds 

 on the nitrate-forming organisms. Soil. Sci. 11: 389-407. PL 1-2. 1921. — Nitrobacter was 

 grown upon washed nitrite-agar and on slants of Niihrstoff-Heyden agar with and without 

 nitrite present. Microscopical examination showed that this organism does not reproduce 

 in liquid cultures of water, urine, peptone-beef infusion, or Niihrstoff-Heyden infusion. The 

 last was non-toxic but beef infusion or peptone-beef infusion contained a non-volatile toxic 

 substance, soluble in ether or alcohol. N itrobacter will live 2-6 weeks in a 1 per cent solution 

 of gelatine, peptone, casein, yeast water, or Nahrstoff-Heyden, or in milk or distilled water. 

 Gelatine, peptone, casein, skimmed milk, beef infusion, and beef extract do not affect the oxi- 

 dation of nitrite; asparagin, ammonium sulphate, and urea decrease it; Nahrstoff-Heyden 

 increases it above that in water controls. Sealed agar slants of Nitrobacter were kept more 

 than 1 year without serious injurj' to the oxidative power. — W. J. Robbins. 



1665. Hardy, F. A preliminary investigation into the occurrence of different kinds of 

 carbonates in certain soils. Jour. Agric. Sci. 11: 1-18. 1921. — Samples of marine silt from 

 the foreshore of the N. W. coastal belt of the Wash were found to contain dolomite. Studies 

 were made to ascertain the effect of dolomite on such processes as nitrification in which the 

 neutralizing effect of a quick-acting base is essential. Culture experiments tended to strengthen 

 the view that dolomite has a definite effect on nitrification, and this view was further 

 strengthened by an investigation of the nature of the carbonate in soils of which the geological 

 and agricultural history is known. A technique for the estimation of the easily decomposed 

 ("Calcitoid") and more stable ("Dolomitoid") carbonates was developed. Marine silts 

 may be expected to contain calcitoid and dolomitoid carbonate; other soils do not generally 

 contain the latter type of carbonate. Cultivation reduces the carbonate content of the soil, 

 especially of calcitoid soils. Acidity may occur in soils containing both types of carbonates 

 when the total carbonate content is greater than the amount considered necessary to prevent 

 acidity. The reason for this is that the dolomite types of carbonate are not easily affected by 

 the weak acids of the soil. — V. H. Young. 



1666. Hardy, F. Substitutes for pen manure. Agric. News [Barabados] 20:21. 1921. — 

 The author discusses various materials used in India to replace pen manure, such as oil cake, 

 green manures, top soil from virgin forests or high jungles, earth from scrub jungles, earth 

 from grass land, and tank silt. Not many of these substances are available to the average 

 West Indian planter, to whom the author suggests the emploj^ment of scrub from waste places, 

 rank herbage (including tall grasses), road sweepings, trimmings of trees, rotted lime or orange 

 skins and seeds, waste green stuff from the banana, cacao and coconut crops, filter and scums 

 from sugar factories, and cotton seed meal. — /. S. Dash. 



1667. HiBBARD, P. L. Sulfur for neutralizing alkali soils. Soil Sci. 11 : 385-387. 1921.— 

 The addition of sulphur to alkali soils was found to reduce the alkalinity and to improve the 

 conditions for plant growth. — W. J. Robbins. 



