209 



station, otliei'.s on similar small i)lats are to be carried out in accordance 

 with the same schedules l)y larmers in diti'ereut i^arts of Saxony under 

 the directiou of the station. Experiments in which the eHects of fer- 

 tilizers and kindred questions are to be studied under circumstances 

 which provide for 'uniformity of soil, regulation of moisture, collecting 

 of all drainage water for analysis, determination of meteorological 

 conditions, and physical and chemical study of the soil, and of course 

 accurate measurement and other desired examinations of the produce, 

 are also to be made in boxes of one cubic meter content. These are made 

 of cement, lined with glass, the joints of which are closed with red lead, 

 and are furnished with tubes at the bottom by which water may be suii- 

 plied or removed, and the Avater table kept at any desired level.* These 

 boxes are surrounded by soil of the same character as that contained 

 in them, in order to make the temj)erature correspond with that of the 

 soil in its natural condition. Deep passageways between the rows 

 of boxes make the management of the drainage tubes easy. Long 

 thermometers running* horizontally at different depths through the 

 side of a similarh^ situated box of soil, serve for observations of soil 

 temijeratures. 



Dr. Wohltmann of the Agricultural Institute of the University of 

 Halle described a series of experiments conducted by himself and 

 Dr. Scheftler during 3 successive years in boxes somewhat similar 

 to those above described. The object was to study the effects of ferti- 

 lizers containing nitrogen, phosphoric acid, and potash, singly and in 

 combination, upon the growth of different plants, and the gain and loss 

 of plant food by the soil under conditions at once normal and capable 

 of measurement and control. The paper was an abstract of a memoir 

 just published,t and not only gave the plan and results of the experi- 

 ments, but discussed the experimental method, which is a modification 

 of that proposed by Prof. P. Wagner. Summaries of this and other 

 l^apers presented at the meeting will be published in the Experiment 

 Station Kecord. 



Dr. Gerlach of the Halle Experiment Station described several sets 

 of experiments which were instituted as part of a series, the object of 

 which is to work out a laboratory method for determining the deficien- 

 cies of soils in plant food. Attention was first given to phosphoric 

 acid. In these experiments the effort is being made to find a solvent 

 which will extract from the phosphoric acid of different soils quantities 

 similar to those which plants can utilize and thus afford an approximate 

 measure of the available as distinguished from the total amount of 



* In visiting this station in company with the writer, Dr. Gilbert of Eothamsted 

 referred to the difficulty experienced there in getting boxes which will not leak, and 

 in filling them satisfactorily with earth. After trials with diiFerent materials glazed 

 earthenware was finally decided upon. 



t Berichte a. d. physiol. Laboratorium und d. Versuchsanstalt d. Landw. Insti- 

 tuts d. Univ. HaUe, 8, 1891. 



