SOILS FERTILIZERS. 623 



are discussed in connection with the characteristics of the different soil forma- 

 tions and their mechanical, physical, and chemical structure. These marsh 

 lands are said to have originated, principally, through glacial action, and 

 gradual rising and sinking of the seacoast. Fourteen different soil formations 

 are described, several of which apparently represent different stages of forma- 

 tion of the same soil caused by alternate rising and sinking of the coast. The 

 majority of these formations are of high or average fertility, being for the 

 most part characterized by a considerable content of lime and humus and an 

 appreciable content of potash and phosphoric acid. The most important types 

 appear to be the muck-sand and muck-clay soils, which contain much humus, 

 lime carbonate, fine sand, and fine clay, and are said to bo the deposits of 

 receding floods. The more recent muck formations are .saline. The le&*s pro- 

 ductive types are tough clays intermixed with coar.se gravel and iron com- 

 pounds. 



The coast marsh districts and the so-called river and l;ike marshes of the 

 region are described with reference to the distribution of the soil types, and dis- 

 cussed from the standpoint of improvement and profitable utilization. 



The soils of Uruguay, J. Puig y Nattino (Min. Indus. [Uruguay], Insp. 

 Nac. Ganadcria y Agr, Bol. 6 {1913), pp. 30+4, pl- i).— This bulletin gives 

 results of physical and chemical analyses of 138 soil samples from different 

 States in Uruguay, a chart showing the location of the soils by States, and a 

 classification of the soils as regards their physical and chemical properties and 

 plant food content. 



The parent rocks and consequently the soil formations are very varied, the 

 soils usually being formed by weathered materials transported from more or 

 less distant points. The predominating soil types show in general sufficiently 

 firm and resistant qualities due to the relatively high content of fine sand 

 and clay. The soils are generally relatively deficient in lime, although some 

 show a high lime content, and are on the whole rich in humus and nitrogen. 

 The phosphoric acid content appears to be usually a little low, the potash 

 content on the whole relatively high. 



The determination of the reaction and the basicity of soils and their 

 importance in soil examination, H. R. Christensen (X. Cong. Internat. Agr. 

 Gand, 1913, Sect. 2, Question 3, pp. 10). — This article discusses the importance 

 and methods of determining the reaction and basicity of soils. It points out 

 their relatiton not only to the growth of higher plants but also to the activity 

 of the microflora of the soil. These determinations furnish a valuable indication 

 of the lime and other fertilizer needs of the soil, the crops best adapted to it, the 

 weeds and other injurious plants, and plant diseases most likely to thrive in it. 



Experiments with water solutions of the soil, G. Leoncini and G. Masoni 

 {8taz. Sper. Agr. Ital., 46 {1913), No. 7-S, pp. 525-539) .—Studies of soil solu- 

 tions showed their power of flocculation to be inversely proportional to the 

 quantity of kaolin remaining in suspension in a solution after a fixed time, 

 comparison being made with the amount held in suspension in distilled water 

 under the same conditions. The powers of flocculation of soil solutions varied 

 with the soil and with the method of preparing the solutions. 



It is concluded th;it the power of flocculation of a soil solution is not only an 

 index of the individual properties of a soil, but also indicates accurate methods 

 of analysis. 



Circulation of nitrates in the soil, L. jNIalpeaux and G. Lefort {A7in. Sci. 

 Agron., 4. ser., 2 {1913), II, No. 6, pp. 705-726, figs. 2; ats. in Chem. A6s., 8 

 {1914), No. 7, p. 1320). — In a continuation of previous experiments (E. S. R., 28, 

 p 720), the authors observed the influence of .sodium nitrate fertilization at 

 the surface and at depths of 5, 10, 17, and 30 cm. and of rainfall and capillarity 

 41074°— No. 7—14 3 



