22 EXPERIMENT STATION EECORD. 



sum. No nitrate accnmulations have been obserred in arid soils free from other 

 water-soluble salts." 



The author believes that the alkali salts, including the nitratas, were de- 

 posited at the time of the formation of the shale from which the soils examined 

 were derived, " and, on the decomposition of this shale in the formation of the 

 soil, the alkali has become incorporated with the latter. The passage of the 

 water through the shale structure also washed out the soluble salts and carried 

 them to the lower lying land." 



Water-soluble matter in soils sterilized and reinoculated, T. L. Lyon and 

 J. A. BizzELL {tfew York Cornell Sta. Bui. 326, pp. 207-224, figs. .4).— The 

 authors briefly review investigations on this subject by others and, in con- 

 tinuation of previous work (E. S. R., 23, p. 316), report studies of the nature 

 of the chemical changes brought about in soils by steaming, particularly as to 

 the relation of the bacterial activity to such changes. Three different soil 

 types were used, the sterilized samples being (1) uninoculated, (2) inoculated 

 with fresh soil, and (3) inoculated with heated soil. 



The results show " there was a gradual decrease in water-soluble matter on 

 standing and this was more rapid in the soil inoculated with fresh soil for 

 several weeks, but after 6 months the soluble matter was higher in the soil 

 thus inoculated. There was an indication that nitrate-reducing organisms were 

 an important factor in determining the quantities of nitrates formed in the 

 soils used. There was no indication that inoculation with fresh soil introduced 

 organisms that lessened ammonia formation, but it is of course possible that 

 such organisms, if introduced, would not thrive in soil previously steamed. . . . 



"At first the soluble matter disappeared most rapidly in all steamed soils 

 inoculated with fresh soil, but the rate of its disappearance gradually dimin- 

 ished until at the end of 6.5 months there was more soluble matter in the soil 

 inoculated with fresh soil than in either the uninoculated soil or in that 

 inoculated with heated soil." 



There was strong evidence to show that toxic matter was the controlling 

 factor in the productivity of steamed soils. 



The quantity of water-soluble matter was not a measure of the relative 

 toxicity of two different soils. The rapidity of oxidation in the soil, as measured 

 by the oxygen requirement, did not always indicate the rate at which toxicity 

 disappeared, although in one case aeration of the steamed soil, and the growth 

 of plants in that soil, both caused a decrease in toxicity. 



Studies in plant nutrition, II, W. H. Jordan {New York State Sta. Bui. 

 360. pp. 53-77, figs. 8). — This bulletin reports experiments with barley, peas, 

 tomatoes, tobacco, buckwheat, rape, and turnips conducted in a forcing house 

 during 1900-1904 for the purpose of ascertaining the essential minimum 

 amounts of phosphoric acid and potash which must be available to plants 

 for maximum growth. 



" In one set of boxes the basal ration supplied all needed elements save phos- 

 phoric acid, this being added in progressive quantities to the several boxes. 

 In the other set of boxes the basal ration supplied all the necessary elements 

 save potash, which was added in progressive quantities to the several 

 boxes. ... 



" The growth of the plants was, in most instances, such as would be satis- 

 factory with field-grown crops, the production of dry matter with barley being 

 in two of the three experiments beyond what could reasonably be expected in 

 a farm crop. Up to a somewhat indefinite point the production of plant 

 substance increased with the increase in the supply of the variable constitu- 

 ents, but beyond this point the utilization of both phosphorus and potassium 



