SOILS FKl{'riLI/KKS. 



15 



rciiioviiii^ tliciii Irdiii (ho box. Tliis. loiicllicr witli the l);il;iiicc used, is shown 

 in figure 1. 'I'lic Jmis woro tlio oniinnry inusi'uni Jars, without tops, having an 

 extended tlan.^c at the top. serving ;is a supi)ort for the jar, thougli the cross- 

 l)ieees were carried through tlie frame luider tlie boxes in order to relicNc any 

 sudden strain upnn tlic flange. Tlicse jars were Ti in. in diameter and Kt in. 

 deep. Tiiey were ail tai'ed by adding small (piartz i)ehhles, and each contained 

 exactly lio ll>s. of soil. In orch'r to jirotect the jdants from high winds and 

 fi'om rain, a detachable roof was made b\- a framework, hinged in the middk! 

 and covered with duck. In order to provide for the growtli of the plants stakes 

 were fastened to the sides of the frame, with holes bored in them at ditferent 

 distances. The roof could, by this device, be adjusted at dilt'erent heights, and 

 was held in place by means of iron staples." 



The detailed results of studies of the effect of small, medium, and large 

 amounts of potash and phosphoric acid on the growth of the cowi)eas and of 

 small, medium, and large amoiuits of potash, phosphoric acid, and nitrogen on 

 oats are reported, but no conclusions are drawn. 



" The experiments begun in Hammonton in 1904, to study methods of develop- 

 ment of the light soils, as well as their adaptability for the growing of forage 

 croi)s, were contimied through the present year." The object in the first case is 

 " to grow profitable forage crops, in succession, by the use of commercial fertilizer 

 alone." Data are given for crops of crimson clover followed by soy beans, rye 



F.(i. !. — lluliinfe for weighing soil pots. 



an(] vetch followed by corn, red clover followed by millet, wheat followed by 

 cowpoas, and oats and vetch grown in IIXI."). 



The measure of soil fertility from the nitrogen standpoint, J. (J. Lipman 

 (New Jersey Sfus. Kitt. 1005, pit. 225-280). — This is a review and contx-ibution 

 to the study of the biological activities of the soil bearing upon the various proc- 

 esses of nitrogen fixation, decay, nitrification, and denitrificatlon, each of which 

 plays a certain role in the nitrogen feeding of the crop, with a view to finding 

 means "to intensify the desirable processes of nitrogen fixation and nitrifica- 

 tion; to suppress the objectionalile denitrificatlon, where it is at all apt to take 

 I)lace ; to sujjpress, likewise, the too rapid oxidation of the organic niattei", and 

 those ithases of decay that might lead to the liberation of elementary nitrogen." 



Series of studies of annnonia prodiiction in peptone solution inoculated with 

 soils of different kinds fertilized in various ways and of experiments with 

 Azotol)acter cultures isolated at various times in 1003, 1904, and 1005 ai-e 

 reported. 



"The cultures of Azotohaeter vinelatKlii, isolated at the beginning of 100.3 and 

 kei)t in the laboratory since that time, were found to have lost none of their 

 nitrogen-fixing power. A similar comi)aiMson of fresh cultures of .1. heuerincki 

 with those isolated a year earlier showed that also this species had retained its 

 original power of fixing atmospheric nitrogen. As to the (pi.-uititative produc- 

 tion of combined nitrogen, .1. riiichiiKlii is markedly suiierior to either A. 

 hrycrincki or .1. chroococcum, with an output frequently more than double that 



