s!^ 



122 EXPERIMENT STATION RECORD. [Vol. 



source of potash for the following: Asparagus (11 years), currants (4 years), 

 mangels (2 years), sugar beets (1 year), corn, ensilage (1 year), corn stover 

 (7 years), sweet-corn stover (1 year), squashes (3 years), carrots (2 years), 

 onions (2 years), celery (1 year), oat hay (1 year), and vetch and oats (2 

 years). The sulphate has proved the better source of potash for the following 

 crops: Asparagus (1 year), blackberries (10 years), raspberries (10 years), 

 strawberries (11 years), rhubarb (12 years), potatoes (12 years), corn, grain 

 (7 years), sweet corn, ears (1 year), cabbages (10 years), soy beans (4 years), 

 alfalfa (4 years), crimson clover (1 year), common red and alsike clover (1 

 year), and mammoth red clover (1 year)." 



The results in the twenty-sixth year of a comparative test of two fertilizer 

 mixtures, one high in potash and low in phosphoric acid and the other high in 

 phosphoric acid and low in potash, showed that for the mixture rich in phos- 

 phoric acid the yield of crib-dried corn was 46 bu. and the yield of stover 5,420 

 lbs. per acre, and for the mixture rich in potash, 35.1 bu. of corn and 5,060 lbs. 

 of stover per acre. 



The results of the eighth year of a comparison of ammonium sulphate and 

 sodium nitrate as a top-dressing for permanent mowings were " in favor of th^ 

 nitrate of soda for the first crop, with very little difference between the two for 

 the second crop, and the no-nitrogen plat producing more rowen than either the 

 nitrate of soda or sulphate of ammonia plats. . . . These results . . . indicate 

 in a striking way that beneficial results are obtained by top-dressing with sul- 

 phate of ammonia and nitrate of soda, and that the results are immediate but 

 not lasting." 



The results of an experiment to study the relative value of different sources 

 of lime on the basis of equal applications of combined calcium and magnesium 

 oxids are briefly noted, medium green soy beans being grown for seed. The fol- 

 lowing comparative yields per acre are reported : With hydrated lime, 31.2 bu. 

 of seed and 2.484 lbs. of straw ; with marl, 30 bu. of seed and 2,435 lbs. of straw ; 

 with ground limestone, 30.02 bu. of seed and 2.359 lbs. of straw ; with no lime, 

 28.86 bu. of seed and 2,273 lbs. of straw ; and with limoid, 35.25 bu. of seed and 

 3,209 lbs. of straw. 



Other general data are also included on the effect of the continued use of 

 fertilizers containing single plant food elements and of different combinations of 

 plant food elements on different crops, and the relative value of different ferti- 

 lizer rotations for top-dressings of grass land. 



Sources of nitrogen compounds in the United States, C. G. Gilbert 

 {t<))uthsn. Inst. Pnb. 2^21 (1916), pp. 12). — This paper discusses the nitrogen 

 situation in the United States and briefly describes the arc method, the cyan- 

 cmid and Haber processes, and the by-product ammonia method of obtaining 

 nitrogen compounds. The cyanamid process and the by-product coking opera- 

 tion are thought to offer the greatest possibilities in the United States for 

 meeting the agricKiltural and other requirements for nitrogen. 



Fixation of air nitrogen and the importance of the resulting fertilizer to 

 agriculture, L. Seidler (Fiihlinp's Landir. Ztg., 64 (1915), No. 21-22, pp. 5^3- 

 5.56). — A number of processes for the fixation of air nitrogen are described and 

 discussed. 



The preparation of superphosphate from phosphorites from Saratov and 

 Perme, N. P. Koblykov {Trudy Kom. Moskov. Selsk. KJioz. Inst. IzslQd. Fos- 

 foritov., Ser. II, 5 {1915), pp. 16-22). — Experiments with the two types of phos- 

 phorite are reported which show that the Perme phosphorite yielded a product 

 containing 16.2 per cent water-soluble phosphoric acid and the Saratov phos 

 phorite from 11.7 to 11.8 per cent. 



J 



