218 EXPERIMENT STATION RECOED. [Vol.38 



returned to the land, the manure to be supplemented with gi-ound limestone, 

 raw rock phosphate, bone meal, acid phosphate, or a highly phosphatic mixed 

 fertilizer, and a small amount of potash (when prices are normal) applied in 

 the course of a systematic crop rotation. 



[Fertilizer experiments], W. P. Bkooks and E. F. Gaskill (Massachusetts 

 Sta. Kpt. 1916, pp. Jf5a-56a). — Progress reports are made on experiments 

 previously noted (E. S. R., 36, p. 121), including comparative tests of manure 

 alone and nitrate of soda, sulphate of ammonia, and dried blood in various 

 fertilizer combinations on Japanese millet; muriate v. sulphate of potash on 

 corn, soy beans, alfalfa, blackberries, and raspberries; manure and various 

 combinations of chemical fertilizers on beets and onions, limed and unlimed ; 

 differ(Mit kinds of phosphates on corn ; kainit, high-grade and low-grade sulphate, 

 muriate, nitrate, and carbonate of potash, and feldspar on mixed grass and 

 clover; fertilizer high in potash and low in phosphoric acid v. one low in potash 

 and high in jihosphoric acid on corn ; various combinations of fertilizers, with 

 and without lime, on corn ; ditferent systems of top-dressing grass ; sulphate of 

 ammonia v. nitrate of soda as a top-dressing for hay lands ; and different 

 methods of applying manure and different kinds of lime compounds on soy 

 beans and corn. 



The yield of onions on plats continuously fertilized with sulphate of am- 

 monia was increased 60 per cent and more by liming. Similar results, but less 

 pronounced, were obtained in case of beets. On plats continuously cropped with 

 onions there was with one exception no benefit from the addition of chemicals 

 to manure. The best source of nitrogen for onions was nitrate of soda and 

 the least beneficial was sulphate of ammonia ; there was little difference in 

 effect between muriate and sulphate of potash. Considering the fact that no 

 potash was applied in 1916 " it would seem that on land in a high state of culti- 

 vation, which has received liberal annual applications of fertilizers containing 

 potash, a good crop [of onions] might be expected for at least one year without 

 the use of any potash." 



In 19 years' experiments with different sources of potash, high-gi'ade sulphate 

 has proved the best source of potash for legumes. No benefit has been derived 

 from the use of feldspar in either large or small quantities. Kainit and muriate 

 have given fully as good results as the other potash salts with timothy and 

 redtop. Potatoes receiving no potash have proved less resistant to blight than 

 those fertilized with potash. 



The largest yields of corn in experiments continued since 1S90 have been 

 obtained where potash was added to the fertilizer used. The results of experi- 

 ments on grass during the past year, in which potash was omitted from the fer- 

 tilizer, " seem to indicate that on permanent mowings, where it has been the 

 custom for several years to apply annually a liberal application of cliemicals 

 or manure, potash may be omitted for at least one year and still a normal crop 

 be obtained." 



The yields of hay on permanent grasslands which had been continuously top- 

 dressed for 9 years with nitrate of soda and sulphate of ammonia were largest 

 in 1916 in case of the nitrate of soda. 



The results of five years' comparative tests of applying manure as it is hauled 

 from the stable in winter and of piling it in large heaps and spreading in the 

 spring were invariably in favor of the latter method of application, although the 

 advantage was small. 



In tests of different forms of lime compounds on corn and soy beans the re- 

 sults appeared to favor hydrated lime and limoid as compared wath marl and 

 ground limestone. The results obtained in these tests also indicated " that 

 land which has received annually a liberal application of manure for several 



