NOTES AND ABSTRACTS. 



531 



Soil Formation, Effect of Climate on. By J. W. Leather {Jour. Agr. Sci. vii. 

 Part 2, pp. 135-6; Sept. 1915). — The author instances two soils of India, viz. 

 the Laterite and the Regur or Black Cotton Soil, the formation of neither of 

 which can be attributed to weather or climate. The former consists largely of 

 aluminium hydroxide; the latter contains up to 10 per cent, of calcium, and 

 its black colour is due to a colloid, not attacked by concentrated hydrochloric 

 acid, containing iron, aluminium, and silica, associated with a small proportion 

 of organic matter. The author suggests that both soils may be a result of 

 bacterial activity. — /. E. W. E. H. 



Soil, The Comparative Effect on Different Plants of Liming an Acid. By B. L. 



Hartwell and S. C. Damon (U.S.A. Agr. Exp. Stn., Rhode Island, Bull. 160, 

 Oct. 1914, pp. 405-446 ; 10 figs.). — This bulletin gives in tabulated form details 

 of over 280 different varieites of plants, including 75 flowering perennials, 25 

 trees, 30 grasses and clovers, and 150 miscellaneous crops, grown upon four plots, 

 equally and liberally treated as regards nitrogen, phosphorus, and potassium. 

 Two of the plots received their nitrogen in form of sulphate of ammonia, and 

 the other two in the form of nitrate of soda. To only one of each pair was 

 slaked lime applied from time to time. The experiments have extended over 

 twenty- two years. 



The difference in the residual effect of sulphate of ammonia and nitrate of 

 soda on the degree of soil acidity is shown to a marked degree, and as the same 

 amounts of lime were added with the two sources of nitrogen, the resulting 

 reaction was liable not to be optimum for the growth of a given plant. 



The plants used included all grades, from those which are positively injured 

 by an application of lime even to a very acid soil, to those which are unable to 

 live on an acid soil and are benefited by lime. — A. B. 



Soils, Absorption of Fertilizer Salts by Hawaiian. By Wm. McGeorge (U.S.A. 

 Agr. Exp. Stn., Hawaii, Bull. 35, Aug. 1914, pp. 1-32). — The soils of Hawaii 

 contain a very high percentage of iron and aluminium compounds, as well as large 

 amounts of organic matter and humus. The experiments were undertaken to 

 determine the absorptive power of these soils with regard to fertilizer salts, such 

 as phosphoric acid (potassium phosphate), potash (potassium sulphate), and 

 nitrogen (ammonium sulphate and sodium nitrate). 



It was found that the fixation of phosphoric acid was higher than the other 

 elements. This is largely due to the basic character of the soils. Crops were 

 found to respond readily to soluble phosphates (sodium phosphate and acid 

 phosphate). There was considerable difference in the physical action of calcium 

 and potassium phosphates ; the calcium salt filtered through the soil as a perfectly 

 clear solution, while the potassium salt had a decided deflocculating action upon 

 the clay. 



Apparently the controlling factors in the fixation of potash are the amounts of 

 lime and magnesia present. The fixing power of the potash is quite marked. 



The fixation of the ammonium nitrogen is controlled by the same factors 

 as for potash. It is, however, not so strongly fixed, and is leached out easily by 

 rains and drainage water. The power of the soil for fixing nitrate nitrogen is small 

 except in case of organic soils. — A. B. 



Soils, The Effects of Strongly Calcareous, on the Growth and Ash Composi- 

 tion of certain Plants. By P. L. Gile and C. N. Ageton (U.S.A. Agr. Exp. Stn., 

 Porto Rico, Bull. 16, Sept. 1914, pp. 1-45; 9 figs.). — This describes a series 

 of experiments with rice, soy beans, bush beans, radishes, sunflowers, sweet 

 cassava, sugar-cane, and pine-apples grown on various plots, one of which con- 

 tained no carbonate of lime, the second approximately 5 per cent., the third 18 

 per cent., and the fourth 35 per cent., of carbonate of lime. 



The following conclusions were arrived at : — 



The growth of bush beans and radishes was unaffected by even 35 per cent, 

 of CaC0 3 ; the growth of sunflowers, soy beans, and sugar-cane was somewhat 

 checked by 18 per cent, of CaC03 ; the growth of sweet cassava was somewhat 

 checked by 5 per cent, and markedly so by 35 per cent, of CaC03 ; while the 

 growths of rice and pine-apples were markedly checked, with the appearance of 

 chlorosis, by 5 per cent, or more of CaC03. The CaC0 3 apparently had no 

 effect on the amount of nitrogen, phosphorus, and potash contained in the 

 various plants. Those plants whose growths were little affected by the CaCO :{ 

 (bush beans, soy beans, radishes, and sunflowers) showed marked decreases in the 

 amount of iron or magnesia in the ash when grown on the calcareous soils. 



The plants whose growths were most depressed on the calcareous soils (rice and 

 pineapples) showed the greatest increases in the amount of lime in the ash and a 

 marked decrease in the amount of the iron. — A. B. 



