277 



iiiiiform by caroful attoiition to tlio subsoil and tliorono-h mixirif? of the 

 suifjice soil. Soils of several kiuils are tested side by side for coiu- 

 parisoii. The ]>laii consists in removing' the S(nl to the depth of a meter 

 (.'{9..'{ inches) ami i('])ia('in<;- it by the soil cliosen ibi- the exi)eriment, which 

 ma.\' be bronght from a distance. For the experiments now being 

 planned at this station typical specimens of five of tlie most important 

 kinds of soil in Saxony have been selected. These are ])laced in ])osi- 

 tion so as to i»rovi<le snndl lields of different tyi)ical soils side by si<le. 

 ICach tield is divided into narrow idats about 4 square rods in area. 

 The i)]ats of each tield are uniform in respect to ])liysical and chendcal 

 characters of the soil, and if tlu^ subsoil is uniform in its water su])]»ly 

 and drainage, as is snpi)osed, they will all have the same quantities of 

 water. The uniformity of soil and water sui)j)ly makes these small 

 jtlats better than large ones ordinarily are. The quantity of water can 

 not be regulated as in the box ex]>erinu'nts, nor can the statistics of 

 income and outgo of plant food and water be determined. 



Of course such arrangements as these are expensi\e. In Dresden, 

 wln're labor is somewhat cheaper than in most places in the T^nited 

 States, the plant for twenty experimental boxes complete cost about 

 $1,()()(). That for the same number of small plats prepared as above 

 described, cost from $750 to three or tVnir times as much, according to 

 the expense of getting, preparing, and esx)ecially transporting the large 

 quantities of soil. But if the expense is considerable at the outset the 

 Avork of carrying on the experiment is less than in ordinary field exjieri- 

 ments, because everything is conveniently at hand and the areas are 

 small. 



For its box experiments the Dresden Station is iilanning a study of 

 tlie acquisition of atmosi^heric nitrogen by plants and soils. While 

 tlie atlliliated station at Tharand is investigating the action of bac- 

 teria in the assimilation of the nitrogen of the air by plants grown 

 in artificial soil, the Dresden Station is to study the practical side of 

 the subject by exi^eriments in natural soil, so devised that the gain and 

 ](»ss of nitrogen may be accurately determined. To this end boxes are 

 to be filled with soils of different kiiuls and lupines grown in them. 

 Some will be treated with bacteria from soils in Avhich lupines have 

 been successfully cultivated, and thus the effects of the inoculation will 

 be observed. Accurate account is to be kept of the amounts of nitro- 

 gen in the soil at the outset, the amounts removed by drainage water 

 and in the plants that are harvested, and the amounts left in the soil at 

 the end of the experiment, which is to last several years. The balance 

 will show how much nitrogen the soil and jilants have gained by the 

 different treatments. — [W. O. A.] 



