118 EXPERIMENT STATION RECORD. 



Per cent. 

 Alumina 0. 148-14. 898 



Phosphorus pentoxid trace- .409 



Sulphur trioxid .000- .694 



Carbon dioxid . 000-28. 998 



Ilumus .084-51.000 



Nitrogen trace- 2.600 



Summary of the soil survey of the State, R. W. Thatcher {Wnshington 

 ^ta. Popular Huh 7, pp. 8). — A popular summary of the above. " 



" Analyses of soils [of grass lands], J. W. Taylor {Univ. Col. Reading,. Dipt, 

 ^gr. and Hort. Bui. 3, pp. 24-26). — Analyses of samples of soil from 2l farms 

 ^h which fertilizer experiments with grass have been carried on are reported, 

 ^he samples were taken to a depth of 9 in. The analyses show very low per- 

 centages of lime in all except two of the soils. Two of the soils which overlie 

 chalk were found to be practically devoid of lime. 



Humid and arid soils of Rio Verde, R. Garcia Oses {Las Tierras dc Riego ij 

 de Temporal en Rioverde. Mexico, 1907, pp. 2-'/). — The nature and causes of the 

 differences between the arid and humid soils of this region are discussed. 



The origin of the fertile soils of western Morocco, L. Gentil ( Compt. Rend. 

 Acad. Sci. [Paris], 1>,6 {1908), No. 5, pp. 2^3-246; ahs. in Rev. Set. [Paris-], 

 5. ser., 9 {1908), No. 7, p. 221). — The author concludes from bis investi- 

 gations that the very fertile black and red soils of this region are the 

 resultant of decalcification of ueogenic calcareous sandstones. Analysis of the 

 black soil shows it to contain 0.15 per cent of nitrogen, 0.25 per cent of phos- 

 phoric acid, 0.46 per cent of potash, nnd 1.39 per cent of calcium carbonate; the 

 red soil 0.2 per cent of nitrogen, 0.08 per cent of phosphoric acid, 0.21 per cent 

 of potash, and 1.79 per cent of calcium carbonate. Chemical analysis does not 

 explain the great fertility of these soils, which is believed to be due mainly to 

 favorable conditions of rainfall and underground water supply. 



Notes on Egyptian and Soudan soils, F. Hughes {Yearbofjk Khediv. Af/r. 

 Soc. Cairo, 1906, pp. 133-140). — The variation in the physical character of Nile 

 soils due to variations in the velocity of the flow of the water from which the 

 soil deposits are formed and to admixture of wind-blown desert sand with the 

 alluvial deposits is pointed out. 



Analyses of 6 representative alluvial soils from Keneh Province are reported 

 which show that " at least in purely alluvial soils, the amount of plant food 

 contained in the various grades of the finer particles of the soil is practically 

 the same." The availability of the plant food constituents as shown by the 

 Dyer method was also very similar in the different grades of soil particles. 



In case of soils with which desert sand has been mixed the plant food con- 

 stituents decrease with an increase of the added sand. 



Analyses of samples of soil from all parts of the Nile Valley show that the 

 alluvial soils in most cases are very similar in composition to Nile silt. Analyses 

 of desert soils not of alluvial origin show that these are much poorer than the 

 Nile soils in mineral constituents and contain only slight traces of nitrogen. 



The alluvial soils contain sufficient potash in available form to render the 

 application of potash fertilizers unnecessary. Although the percentages of total 

 and available phosphoric acid are larger than are usually considered sufficient 

 for needs of crops the soils are as a rule benefited by application of phosphatic 

 fertilizers. It is suggested that the inefficiency of the phosphoric acid in these 

 soils may be due to the deficiency of organic matter. In other words, in soils 

 which are naturally poor in organic matter it is necessai'y to set a somewhat 

 higher figure as the limit below which phosphatic fertilizers may be dispensed 

 with. 



