26 EXPERIMENT STATION RECORD. [Vol.40 



The soil is naturally rich in potash and applications of potash result in little 

 or no crop increase, but there is an increase in the amounts of potash taken up 

 by the crops. It was found that on the average for a 5-crop rotation the crops 

 harvested from the soil treated with potash removed " in a given weight of 

 harvest, 40 per cent more potash than a like harvest weight from the unfer- 

 tilized land contains — that is, both chemical solvent and plant agree in indi- 

 cating a higher availability for at least part of the potash in the potash-dressed 

 soil. Moreover, the crops grown the second year after the application show a 

 greater potash excess than those to which the potash fertilizer is directly ap- 

 plied. Crediting the fertilizer potash with the excess only of the potash in the 

 crops from the fertilized soil, the crops have used not more than one- fourth of 

 the potash dressings applied." 



The general conclusion reached is that " much of the potash applied as fer- 

 tilizer remains in the surface soil in a state highly available to crops, that most 

 of it remains there in a condition of lower availability, and that the losses by 

 drainage have probably not been great." 



Potash situation growing serious, R. C. Randall (Chcm. Kngin.. 26 (1918), 

 No. 12, pp. ^59-.'f62). — This article reviews the present situation with reference 

 to the extent, development, and possibilities of a domestic supply of potash in 

 the United States. 



It is shown that the present production Is far short of the 250,000 tons of 

 pure potash which is estimated to be the annual need of the United States. 

 Data are given for the production from the Nebraska lakes, Searles Lake, 

 alunite, cement works and blast furnaces, and kelp. 



The potassium problem and the utilization of olive oil residue in Italy, 

 G. L'Abate (Abs. in Internet. Inst. Agr. [Rome]. Internet. Rev. Sci. and Praet. 

 Agr., 9 (1918), Xo. 8. p. 931).— It is shown in this article that the 16.500.000 

 bu. of olive oil residue produced annually in Italy contains about 141.320 cwt. 

 of potash obtainable by extraction, besides a considerable amount of nitrogen. 



Production of lime in 1917 ( U. 8. Qeol. Surrey Vers* Bui. 384 (1918), p. 4).— 

 According to revised figures, tlio total production of limo in the United States 

 in 1917 was 3.786,364 short tons, the output of 595 plants, as compared with 

 4,073,433 tons, the output of 77S plants in 1916. The average price ineroas.-d 

 from about $4 in 1016 to $6.29 in 1917. The amount of lime used in agriculture 

 in 1917 was 48S.297 tons. 



Analyses of commercial fertilizers, R. N. Rkackktt and EL M. Stackhouse 

 (South Carolina Sta. Bui. 197 (1918), pp. 3-62).— This reports the actual and 

 guarantied analyses of 1.474 official samples of commercial fertilizers and 

 fertilizing materials inspected during the season of 1017-18. A total of 236 

 samples fell below the commercial value based on the guaranty. 



AGRICULTURAL BOTANY. 



Hardening process in plants and developments from frost injury. R. R. 

 Harvey (Jour. Agr. Research [U. S.], 15 (1918). Xo. 2. pp. 83-118, pis. S, tigs. 

 S). — A study was made of the practice of hardening plants to determine, if pos- 

 sible, the physiological basis of this practice and the mechanism of frost injury. 

 The investigations, which were carried on in the Bureau of Plant Industry. 

 U. S. Department of Agriculture, were made on the effect of hardening by 

 exposure to cold in case of cabbage, tomatoes, and a number of other plants. 

 Plants were kept in constant temperature chambers at 3 and 5° C. using 

 18 and 25° as controls. After 5 days' exposure to 3°. cabbages were not Injured 

 by 30 minutes' exposure to —3°. although frozen stiff. The maturity of tissues 

 was found to be an important factor in frost resistance although during the 



