520 EXPERIMEN^T STATION RECOED. 



ground phosphate 50. The average trade values of the fertilizers during the 

 six years were as follows (phosphoric acid in superphosphate taken as 100) : 

 Thomas slag 88, bone meal 78 (61 if the value of the nitrogen therein be con- 

 sidered), and Algiers phosphate 50. 



On sandy soils low in lime the Thomas slag proved of about the same value 

 as superphosphate, and is therefore to be preferred in this case, and also for 

 meadows, when the price of phosphoric acid in the slag is 10 per cent lower 

 than that of superphosphate. When phosphoric acid in Algiers phosphate costs 

 only one-half that of superphosphate, it can be applied to advantage on sandy 

 soils low in lime and on meadows, also as a first application on new marshes 

 whose acid reaction tends to render its phosphorus soluble and available to 

 crops. 



Chemical examinations were made of the main types of soils included in the 

 experiments, especially with reference to reaction, basicity, and acid-cleaving 

 power (Baumann's method). The results obtained indicate that superphosphate 

 is a good standard by which other phosphatic fertilizers may be judged, and 

 that the application of bone meal (or ground phosiihate) is not to be recom- 

 mended on soils that have been found to contain basic substances, either by the 

 reaction test or by the biological basicity determination (Azotobacter test). 



The utilization of natural phosphates and silicious lime as fertilizers, T. 

 Pfeiffeb {Engrais, 28 {1913), No. 37, pp. 1022, 1023).— This is a summary of 

 work on this subject by various investigators, including the author. 



The general conclusion is that under certain conditions and for certain pur-- 

 poses natural phosphates may be valuable as a fertilizer but that the value of 

 certain novelties in the treatment of these phosphates to increase their effective- 

 ness remains to be determined. The preponderance of evidence seems to indi- 

 cate that silicious lime is not only not harmful in the soil but may be beneficial. 



Analyses of agricult\iral lime sold in Maryland, H. B. McDonnell et al. 

 (Md. Agr. Col. Quart., 1913, No. 60, pp. 11).— The results of inspection of agri- 

 cultural lime under the state law which went into effect in June, 1912, are 

 reported with brief explanatory notes. 



Note on the influence of tlie lime-magnesia ratio upon plant growth, O. 

 LoEW (Jour. Indus, and Engin. Cheni., 5 {1913), No. 3, pp. 251, 258). — Referring 

 to an article by Gile and Ageton (E. S. R., 28, p. 812) showing that citrus trees, 

 pineapples, and sugar cane thrive well on soils containing wide ratios of lime to 

 magnesia, the author maintains that citrus trees and pineapples belong to the 

 class of lime-loving plants which are capable of maintaining a suitable lime- 

 magnesia ratio by precipitating as oxalate the excess of lime taken up from the 

 soil. The results with sugar cane are held to be inconclusive. 



On the influence of the lime-magnesia ratio, P. L. Gile and C. N. Ageton 

 {Jour. Indus, and Engin. Chem., 5 {1913), No. 7, pp. 56.'i-567). — The article cites 

 the results of experiments with bush beans on soils containing varying amounts 

 of lime which showed that the lime-magnesia ratio in the plants grown bore no 

 relation to the ratio of the substances in the soil. " Bush beans appear to be 

 Independent of the lime-magnesia ratio in these soils and also of the increasing 

 amounts of carbonate of lime. . . . Since the lime content of the plants re- 

 mained constant vnth increasing amounts of lime in the soil it does not seem 

 possible that this plant could have adapted itself to the conditions by precipita- 

 tion of lime as oxalate." 



Pot culture experiments, 1910-11-12, J. A. Voelcker {Jour. Roy. Agr. 

 Soc. England, 73 {1912), pp. 311t-S38, pis. 7).— These included experiments in 

 continuation of those of previous years (E. S. R.. 23, p. 319) on the influence 

 of lithium, zinc, and lead salts on wheat, and on the relation of lime to mag- 

 nesia in soils. 



