214 EXPERIMEKT STATION RECORn. [Vol. 41 



The movement of plant food within the soil, E. Van Alstine (Soil Sci., 6 

 {1918), No. J/, pp. 281-308). — This paper, a thesis presented to the Graduate 

 Scliool of the University of Illinois, describes investigations in which a study 

 was made of the total amount of the various plant food elements present iu 

 samples of soil from long-time fertilizer plats, including tlie " parli " plats at 

 Rothauisted and the plats of the Pennsylvania and f)luo experiment stations, 

 in order to determine the ultimate fate of the fertility elements added to the 

 soil as fertilizers when not completely removed by the crop. The total amount 

 of organic carbon, ntirogen, phosphorus, potassium, magnesium, and calcium 

 was determined in the Rothamsted soil for samples representing strata of 

 from to 3 in., 3 to 6 in., and 6 to 9 in., respectively. In the case of the 

 Pennsylvania and Ohio soils the observations were confined to a study of the 

 phosphorus content of strata from to Gg in., 6§ to 13J in., and 13J to 20 in. 



Summarizing the results secured, the author concludes that "when phos- 

 phorus is used as a fertilizer, it remains almost where it is placed in the soil 

 until removed in crops or removed by some such process as erosion by water or 

 wind action. The addition of alkali salts (sulphates of potash, soda, and mag- 

 nesia ) seems to encourage the utilization of phosphorus from the surface stratum, 

 especially by legume plants, which probably also secure nitrogen chiefly from the 

 soil air in the surface stratum. There may be some loss of nitrogen through 

 drainage, but when other fertility conditions are right and crops are kept on 

 the ground all through the growing season, this loss is reiy small and there 

 is a tendency for nitrogen, added in the form of ammonia, to accumulate in the 

 surface soil, probably in plant roots and residues. Potassium, though easily 

 and quickly fixed in soil, is more subject to movement within the soil as a re- 

 sult of fertilizing with other salts and in this way may be leached beyond the 

 reach of plant roots. Carbonates are rather easily washed from the soil even 

 when no other treatment is given, but much more readily washed out when am- 

 monium salts are used. The loss of magnesium is brought about by the use of 

 ammonium salts as fertilizers. Calcium decreases with the loss of carbonates. 

 Also, when alkali fertilizer salts are applied, it decreases more rapidly than 

 acidity develops. Ammonium salts cause as marked a loss of calcium as of 

 carbonates, and its loss occurs relatively as rapidly as the acidity develops." 



A list of the references cited, comi)rising 45 titles, is appended. 



The presence of aluminum as a reason for the difference in the effect of 

 so-called acid soil on barley and rye, B. L. Haetwell and F. 11. Pember (Soil 

 ScL, 6 {1918), No. J{, pp. 259-279, figs. 2).— This paper, a contribution from the 

 Rhode Island Experiment Station, describes investigations made iu an effort 

 to ascertain the cause of the unlike effect of acid soils on different kinds of 

 plants. Rye was selected as a plant which grows well on acid soils and barley 

 as one which is materially injured by the same conditions. 



Seedlings of both rye and barley were found to be affected about the same 

 by a given amount of acidity in connection with a nutrient culture in either 

 water or sand, while sterilization of tbe soil either with heat or toluol failed 

 to produce any change which with certainty influenced diffei'ently the two kinds 

 of seedlings. Hydrogen peroxid, dihydroxystearic acid, manure extract, am- 

 monium sulphate, potassium permanganate, chromium, and silicon affected the 

 two plants about alike, while an aqueous extract of an acid soil affected them 

 the same as the acid soil itself. The toxic principle of the extract was con- 

 centrated in the residue upon distilling, the distillate being nontoxic. Both the 

 dialyzate and diffusate resulting from dialysis of the extract had the same effect 

 upon rye and barley, while tlie ash of the soil extract, when brought into solu- 

 tion, had the same effect as the acid soil. 



