820 EXPEEIMENT STATION RECORD. [Vol.36 



which is richer in protein and therefore higher in reeaing vame than one 

 grown with a deficiency of these materials, even though tlie former be no more 

 in quantity than the latter." The importance of carbonate of lime is further 

 shown " In making available the nitrogen of the soil organic matter, and also 

 in maliing conditions favorable for the accumulation of atmospheric nitrogen 

 by means of leguminous crops." 



Banana stalks as a sovirce of potash, H. B. Billings and A. W. Chkistie 

 (Jour. Indus, and Engin. Cheni., 9 {1911), No. 2, pp. 153, i54).— Analyses made 

 at the California Experiment Station of dried banana stalks obtained from 

 fruit markets showed that they contai.i as much potash as kainit and compare 

 favorably with dried kelp as filler for commercial fertilizer. Charring and 

 leaching of banana stalks yielded 27 lbs. of 90 per cent potassium carbonate 

 per ton. The possibility of collection and treatment on a small scale is sug- 

 gested. 



Production of potash in 1916 (U. S. Geol. Survey, Press Bui. 310 {1911), 

 p. 1). — It is estimated from nearly complete statistics collected by the U. S. 

 Geological Survey that " the total production of potash salts and potash prod- 

 ucts in the United States in 1916 was close to 10,000 tons of potash (K2O), 

 with a net value at point of shipment of at least $3,500,000. figured at the pre- 

 vailing selling prices." This is ten times the value of the production reported 

 for 1915 and it is thought that the total for 1917 will be still greater. The 

 production in short tons of available potash was as follows : Natural salts or 

 brine 8,850, alunite and silicate rocks, including furnace dust recoveries, 1,900, 

 kelp 1,110, ashes 220, and miscellaneous industrial wastes 1,750. 



The largest output came from the Nebraska alkali lakes, but natural saline 

 deposits elsewhere are beginning to make important contributions. It is stated 

 that an organic source of high-grade potash similar to kelp " has been quietly 

 developed, which has proved more productive." 



Vegetation experiments: Comparison of basic slag with other phosphates, 

 J. G. Llpman and A. W. Blaib (iVeto Jersetj Stas. Rpt. 1915, pp. 229-234).— 

 This is an account of a continuation of experiments reported in 1913 (B. S. R., 

 32, p. 518) in which basic slag was compared with other phosphates. 



The experiments " indicate a somewhat higher availability for the phosphoric 

 acid of basic slags than has generally been assigned to such materials. If they 

 are thus available for a single crop grown in quartz sand, there certainly 

 seems good reason for believing that they would be even more available under 

 normal field conditions." 



The relative availability of acid phosphate and raw rock phosphate in 

 Indiana field tests, S. D. Conner {Jour. Indus, and Engin. Chem., 9 {1917), 

 various crops made at the Purdue Experiment Station, in which acid phosphate 

 and raw rock phosphate were compared, are reported. It was found that acid 

 phosphate returned a crop increase over six times as profitable per acre and 

 over seven times as profitable per dollar invested as that returned by raw rock 

 phosphate. 



" By calculating the phosphoric acid in all the crops grown, it is found that 

 224 lbs. of PzOe have been recovered in the total increase caused by acid phos- 

 phate and 147 lbs. of P2O. have been recovered in the total increase caused by 

 raw rock phosphate. These amounts of PjOs are approximately one-twelfth of 

 the phosphoric acid applied in the acid phosphate and one eighty-fifth of the 

 phosphoric acid applied in the raw rock phosphate." 



Raw phosphate rock as a fertilizer, C. E. Thokne {Ohio Sta. Bid. 305, pp. 

 221-211, figs. 8). — This bulletin gives a review of work bearing on the .subject 

 reported from eight state experiment stations and from German sources, and 

 gives a more extended report of experiments conducted at the Ohio Station 



