730 EXPERIMENT STATION RECORD. 



Phosphates: Their importance to New Zealand farmers, B. C. Aston {Jour. 

 Agr. [l^cw ZealA, 7 (1913), Nos. 1, pq). 1-9, fig. 1; 2, pp. 115-126, figs. 3).— 

 It is pointed out that phosphorus is probably the principal element of plant food 

 needed in New Zealand soils. Of analyses of 4SS siimples of these soils classified 

 in this article 11 showed a deficiency in available potash, 26 a deficiency in 

 nitrogen, and 165 a deficiency in available phosphoric acid. The response of 

 the soils to phosphatic fertilizers clearly indicates the same need, and this is 

 also reflected in the imports of fertilizers in which phosiDhates very largely 

 predominate. 



There was imported into New Zealand for fertilizing purposes during the 

 year ended March 31, 1913, 9,281 long tons of bone dust, 32,964 tons of super- 

 phosphate, 20,133 tons of basic slag, and 25,033 tons of guano and rock phos- 

 phate. The Otago phosphate mines of New Zealand yielded about 8.000 tons. 

 Potassic and nitrogenous fertilizers are imported to a comparatively small 

 extent. 



The author recommends for New Zealand the system of fertilizing advocated 

 by Hopkins, and methods of experimenting with phosphates are described. 



Progress in the fixation of atmospheric nitrog'en, T. C. Pinkebton {Amer. 

 Fert., 39 {1913), No. 7, pp. 10, 12, 16). — Progress in the manufacture of calcium 

 cyanamid; calcium, sodium, and ammonium nitrates; synthetic ammonia; and 

 aluminum nitrid, using the free nitrogen of the air, is reviewed. 



It is estimated that the world's production of cyanamid in 1913 will be 

 225,000 tons, used principally in the United States 48,000 tons, Norway and 

 Sweden 60,000 tons, Germany 40,000 tons, Italy 30,000 tons, Switzerland 10,000 

 tons, France 7,500 tons, and Japan 7,500 tons. Its use in mixed fertilizers is 

 increasing. Calcium nitrate is made principally at Notodden, Norway, where 

 sodium and ammonium nitrates are also made. The preparation of the latter 

 is the latest important development in the manufacture of synthetic nitrogen 

 compounds for fertilizing purposes. These nitrates are all now on the market. 

 A factory is being erected for the production of synthetic ammonia. The 

 aluminum nitrid process has been perfected but not tested on a large scale. 

 It yields both ammonia and alumina. Its profitable operation depends in large 

 measure upon the price which can be obtained for the alumina. 



The partial sterilization of the soil by means of caustic lime, H. B, Hutch- 

 inson {Jour. Agr. Set. [England], 5 {1913), No. 3, pp. 320-330, pi. 1; abs. in 

 Jour. 8oc. Chein. Indus., 32 {1913), No. IJf, p. 761).— "The known actions of 

 lime in improving the physical condition of a soil, neutralizing acidity, and 

 rendering plant foods available by chemical action are not suflicient to account 

 for many of the results obtained in practice by the application of lime. It is 

 now shown that caustic lime in sufficiently large quantities produces effects 

 intermediate in character between those produced by volatile antiseptics and 

 those induced by high temperatures. The larger protozoa and many bacteria 

 are killed, and the organic nitrogenous constituents of the soil are decomposed. 

 When all the lime has been converted into carbonate, a period of active bac- 

 terial growth ensues, with increased production of plant food. Pot experiments 

 gave results in agreement with those of bacteriological and chemical analyses. 

 A poor arable soil, containing a suificiency of calcium carbonate, gave increased 

 yields after application of 0.5 per cent of caustic lime. A rich garden soil after 

 the application of lime (up to 1 per cent) gave decreased yields in the first 

 crop, but largely increased yields in the second crop." 



The lime-magnesia ratio in agriculture, P. Larue {Rev. Sci. [Paris], 51 

 {1918), II, No. 2, pp. 48-50). — Investigations on this subject are reviewed and 

 the practical significance of the lime-magnesia ratio from the standpoint of fer- 

 tilizing the soil is briefly considered. 



