SOILS PEETILIZERS. 623 



Report of the chemist, P. L. Gile {Porto Rico Sta. Rpt. 1912, pp. 18-22).— 

 A brief survey of the work of the year is given, with special reference to a 

 study of the fertilizer requirements of a typical red sandy soil, analyses of 

 which showed it to be strongly acid and deficient in all of the principal mineral 

 constituents. A method of detecting lime in plant ashes is described (seep. 609). 



Relation of calcareous soils to pineapple chlorosis, P. L. Gile (Porto Rico 

 Sta. nut. 11, Spanish Ed., pp. 53. pis. 2).— The English edition of this bulletin 

 has already been noted (E. S. R., 26, p. 121). 



Soil acidity and liming', A. R. Whitson and W. W. Weir (Wisconsin Sta. 

 Bui. 230, pp. 33, figs. 12). — This is a somewhat popular presentation of results 

 of investigations on this subject. It is shown that two-thirds of the soils of 

 Wisconsin are acid and that these acid soils are usually deficient in available 

 phosphorus. The acid soils are unfavorable to the growth of leguminous plants 

 but respond profitably to applications of lime, which improves the growth of legu- 

 minous plants and thus increases the nitrogen supply of the soil. Special atten- 

 tion is called to the necessity of liming and inoculation for the successful 

 growth of alfalfa on acid soils. The principal kinds of lime and the best 

 methods of application are discussed. 



The Illinois system of permanent fertility, 0. G. Hopkins (Illinois Sta. 

 Circ. 167, pp. 20, figs. 12).— In this address before the Illinois State Farmers' 

 Institute the author emphasized the great economic importance " of utilizing 

 mineral plant food from the abundant natural supplies nearest at hand, such as 

 Tennessee phosphate rock, Illinois limestone, and the potassium minerals al- 

 ready present in our normal soils," and of drawing the necessary supplies of 

 nitrogen from the air by means of leguminous plants. 



Shall we use " complete " commercial fertilizers in the corn belt? C G. 

 Hopkins (TUinois Sta. Circ. 165, 2. rev. ed., pp. 14; 3. rev. cd.. pp. 18; 4. rev. 

 ed.. pp. 20, figs. 5). — In this circular the author explains conditions under which 

 the use of complete fertilizers may be very wasteful, and maintains "that in 

 profitable systems of general farming nitrogen should be secured from the air. 

 potassium should be liberated from the inexhaustible supply naturally contained 

 in all normal corn-belt soils, and that phosphorus should be purchased and ap- 

 plied liberally in low-priced fine-ground natural rock phosphate, ground lime- 

 stone (likewise a low-priced natural fertilizer) also being used where needed." 



A study of the effect of fertilizers on the soluble plant food in the soil 

 and on the crop yield, W. B. Ellett, H. H. Hill, and S. M. Hekeick ( Virginia 

 Sta. Rpts. 1911-12, pp. 116-132). — This article summarizes the results of a five 

 years' study of the effect of different kinds and combinations of fertilizers on 

 the soluble plant food in the soil of field plats cropped continuously to com, 

 and of the possibility of correlating determinations of available plant food by 

 chemical means with crop yields. 



The results showed in brief that " fifth-normal nitric acid will detect phos- 

 phates when added to soils of limestone derivation and will show an increase 

 in phosphoric acid the following year, notwithstanding the drain on the soluble 

 phosphates by the crop." It was not possible, however, to make any correla- 

 tion between plant food present, as measured by fifth-normal nitric acid, and 

 the yield because of sm increase in the soluble phosphoric acid. The available 

 phosphoric acid of the soil as thus measured was not reduced by the cropping as 

 much as the phosphoric acid content of the crop would mdlcate. 



" By the use of commercial fertilizers there is an increase in the total plant 

 food of the soil, as well as in the crop yield. The available phosphoric acid 

 in the soil has been increaspd where complete fertilizers were api»lied, . . . not- 

 withstanding the increase in yield on this plat. 



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