724 EXPERIMENT STATION RECORD. 



" The frequent occurrence of dihydroxystearic acid is of special interest and 

 significance because of its linown tiarmful properties to plants. One-third of 

 all the soils examined showed the presence of this compound. It was found in 

 virgin soils as well as in soils under long cultivation ; in soils continually 

 cropped as well as in soils under permanent sod; in soils from the Atlantic 

 coast; in soils from the Pacific coast; and in soils from the Gulf States. This 

 comix)und is. therefore, a common soil constituent and is likely to be encoun- 

 tered in soils anjTvhere. Its formation or its accumulation is doubtless due 

 to local conditions in any one section, but these local soil conditions are not 

 confined to any region of the United States and probably not to any country 

 or continent. 



" When the soils examined are separated into good and poor soils, as based 

 on field observations, their relationship with dihydroxystearic acid is rather 

 striking. Among the good soils only 2 contained dihydroxystearic acid and 

 they were of only moderate productivity. Among the i)oor soils the percentage 

 of those containing this compound was 51. Of the soils which had a record 

 for infertility, the dihydroxystearic acid was found in each and every case. 



" Judging from the foregoing relationships established by this investigation 

 it would seem that dihydroxystearic acid is either a direct or indirect factor 

 in the low productivity in soils; direct by virtue of its harmful effects on grow- 

 ing crops, indirect as an indicator of other compounds or conditions which 

 cause soil to become less productive and even infertile. It is not possible to 

 state from the data at hand that dihydroxystearic acid is the only factor which 

 contributes to the infertility or unproductivity in those soils in which it was 

 found, for it must be remembered that this is only one of many compounds, 

 both organic and inorganic, harmful and beneficial, which exist In soils, any 

 and all of which play a part in its relative fertility and infertility. It is 

 certain, however, that the determination of even this one constituent leads 

 to a recognition of the kind of infertility in the soils examined and is, there- 

 fore, a readily recognized symptomatic factor of poor soil conditions." 



The distribution of organic constituents in soils, O. Schreiner and E. C. 

 Lathrop (Jour Franklin Inst., 172 (1911), No. 2, pp. Ili5-151). — This article 

 is based upon results of investigations more fully reported above. 



A peculiar soil sickness, J. Hudig (Landw. Jahrb., ^0 (1911), No. 3-lf, pp. 

 613-6J,-'i. pi. 1; abs. in Ztschr. Angew. Chem., 24 {1911), No. .',1, p. 1976).— Fur- 

 ther investigations on the so-called "oat sickness" of the soils of Dreuthe and 

 Groningen (E. S. R., 21, p. 115) are reported, and deal with field and pot 

 experiments to test the action of different fertilizers on such soils. 



The sickness is not confined to moor soils, as was at first supposed, but occurs 

 also on sandy and clay soils. Although the investigation is not complete, the 

 author believes that the sickness is due to changes in the composition of the 

 humus caused by continued application of lime and physiologically alkaline fer- 

 tilizers. 



A comparison of soil disinfectants, O. Loew (Porto Rico Sta. Rpt. 1910, pp. 

 17-19). — Comparative tests of chlorid of lime, potassium permanganate, tri- 

 cresol, and carbon bisulphid on " sick " soil planted to lilies are reported. The 

 largest production of flowers and seed was obtained on the plat treated with 

 chlorid of lime, which is considered the best and cheapest of the soil disinfect- 

 ants tested. 



Importance of soil reaction in relation to soil investigations and produc- 

 tiveness, M. Weibull (Meddel. Alnarps Lab., 1911, No. 12, pp.32). — This article 

 ix?ports studies of the extent to which the solubility of the plant food in 

 the soil, the effect of fertilizers, and the yield of crops, depend upon the reaction 

 of the soil. 



