726 EXPEEIMENT STATION RECORD. 



The results show that assimilable phosphates become inactive in the soil the 

 second or third year after application. Different species of plants vary in 

 their capacity to utilize the phosphoric acid naturally present in the soil and 

 therefore vary in the response that they make to applications of phosphatic 

 fertilizers. The superiority shown the first year by superphosphate on account 

 of its finer division and better distribution becomes very slight the second year 

 and soon disappears, so that the three forms of chemically prepared phosphates 

 used in these experiments showed about equal fertilizing values. See also the 

 article noted above. 



The effect of cow dung on the availability of rock phosphate, B. L. Hart- 

 well and F. R. Pember {Rhode Island Sta. Bui 151, pp. 165-174, pi. 1). — "This 

 bulletin contains the results of a pot experiment in which is ascertained the 

 effect of finely ground rock phosphate, or floats, and cow feces or dung, used 

 both singly and combined, on the growth of Japanese millet (Panicvm cnis- 

 galli) and a succeeding crop of oats. 



" Previous to drying, grinding, and mixing with the soil, the fresh dung was 

 stored for about 9 months, not only by itself, but also in an intimate mixture 

 with floats." Portions were stored in a shallow pan, allowing free access of 

 air. Other portions were packed in a bottle until the latter was completely 

 filled, and stoppered so that only a small amount of air was present. 



The soil used in the experiments had been limed and was deficient in phos- 

 phoric acid, but was supplied with optimum amounts of nitrogen and potash. 



" The increase caused by the floats alone added to that caused by the dung 

 alone was about equal to that obtained when both were applied together; and 

 it made practically no difference whether the dung and floats were first brought 

 together when they were added to the soil at the time of planting, or had been 

 kept in a moist mixture during the previous 9 months." 



The results therefore indicate that practically no increase in available phos- 

 phoric acid resulted " from mixing fresh cow dung and floats together for a 

 mmiber of months before applying them to the land." 



The action of calcium carbonate in the fertilizing of oats with monocal- 

 cium and dicalcium phosphate, W. .Simmermacher {Landtc. Vers. Stat., 77 

 (1012), Xo. 5-6, pp. Jf.'il-.'ill, fig. 1). — Pot experiments and chemical studies are 

 reported which led to the conclusion that calcium carbonate does not reduce the 

 fertilizing effect of monocalcium phosphate although it reduces the assimilation 

 of phosphoric acid by the plant. In case of dicalcium phosphate, however, cal- 

 cium carbonate strongly depressetl both the yield and assimilation of phosphoric 

 acid. The bearing of the results on the law of minimum as set forth by 

 Mitscherlich (E. S. II.. 25, p. 825) is discussed. 



The mechanism and fertilizing action of sulphur, E. Botjllanger and 

 DuGARDiN {Compt. Rend. Acad. Sci. [Paris], 155 {1912), No. J,, pp. 327-329; abs. 

 in Rev. Sci. [Paris], 50 {1912), 11, No. 5, pp. 156, 157; Rev. Vit., 38 {1912), 

 No. 976, pp. 250-252; Chem. Zenthl., 1912, II, No. 16, pp. 1392, 1393).— The 

 favorable action of flowers of sulphur is attributed to its effect on the bacteria 

 which break down the nitrogenous matter of the soil to ammonia, and also on 

 the nitrifying organisms. In the presence of sulphur the plant is able to 

 obtain a large amount of directly assimilable ammonium salts. Since the 

 ammonia is formed exclusively fi'om the nitrogenous matter of the soil, it is 

 necessarj' to add organic nitrogenous fertilizers to the soil to counterbalance 

 the rapid removal of nitrogen by i)lants imder such conditions. 



Action of manganese oxid (MnO-) on organic nitrogenous compounds with 

 reference to use of the oxid as feritlizer, G. Leoncini and C. Pieri {Staz. Sper. 

 Agr. Itah, .',5 (1912), No. 3. pp. 22.'i-2.',.', ; ahs. in Chcm. Zenthl., 1912. I. No. 20, 

 pp. 1035, 1636). — It was found in these experiments that ammonium compounds 



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