620 EXPERIMENT STATION RECORD, 



retloiulite, especially in case of siuniiu'r Sijiiasli, crimson clover, Japanese millet, 

 Adzuki beans, and several other plants. 



In case of crimson clover and Adznki beans the raw redondite seemed to be 

 more beneficial than the roasted. The roasted redondite was of little value in 

 case of beets and cabbage on limed land. "Double superphosphate particu- 

 larly, and in some cases dissolved boneblack and acid phosphate, proved rela- 

 tively inefficient upon the unlimcMl land, and a few instances of the same kind 

 were observable even where the land had been limed, particularly in the case of 

 those plants which are liable to injury upon soil which strongly and intensely 

 reddens blue litmus paper and which is at the same time practically devoid of 

 carbonate of lime. 



" Liming, instead of proving injurious in connection with the soluble phos- 

 phates, as is so often alleged, proved decidedly helpful in the majority of cas(>s, 

 and even in many instances with plants which are not particularly in need (if 

 liming. The results seem to indicate that in a soil deficient in or devoid of cai-- 

 bonate of lime and well supplied with the oxids of iron and aluminum, limhig 

 may extend the period of efficiency of the soluble phosphates possibly by com- 

 bining with much of the phosphoric acid at once, and thus holding it in more 

 assimilable combinations than if it were possilde for it all to unite immediately 

 with the iron and aluminum oxids. . . . 



" Double superphosphate seemed to be the least adapted to acid soil of anv 

 of the soluble phosphates, namely, the dissolvc^d bone, dissolved boneblack. and 

 acid phosphate. 



" Finel.v ground unacidulated steamed bone failed to fully meet the needs of 

 some of the crops in the earlier years, but this c*onditi(m soon ceased and it has 

 given excellent results for several years, and has shown a much greater effi- 

 ciency than the floats, even though a much larger quantity of ])liosplioric acid 

 had already ])een applied in the latter than in the bone. 



"Basic slag meal has iiroved throughout to be a highly eflicient phosphatM- 

 manure. Its relative (Efficiency has Ik'cu particularly high where those plants 

 have been grown which are lu'liied liy liming. This is doubtless due in part to 

 the fact that it contains far mor(> lime than bone meal or floats. The use of 

 fine-ground bone, basic slag meal, and floats has tended continually to make the 

 unlinuHl land more favorable to clover." 



In general there was little or no evidence that the nitrogen of the bone and 

 dissolved bone was of particular advantage in incn-asing the yields obtained 

 with these materials. 



It is pointed out that the n^sults in general show that care should be taken to 

 distinguish between jivailable and soluble i)hosph<iric acid in tiie selection of 

 fertilizers. It is also thought that the results show that the Rhode Island 

 gardener and general farmer will do well to exercise caution in the use of floats, 

 confining this use to especially favorable conditions, such as moist soils rich in 

 decaying vegetable matter, and in case of such ci-ops ;is cei'tain legumes, Indian 

 corn, millet, and possibly wheat and oats, which seem better adapted to utilizing 

 the material to advantage than certain vegetables. 



Comparative fertilizer tests of Thomas slag and agricultural phosphate, 

 Clausen {FUJiHih/'s Zt<j., .',.', (Ifioi;). Ko. ID. pp. (I'/O-din. fuin. U; Mitt. 

 Deut. Landw. Gesell, 21 (IMG), No. J,7. pp. /,.'/S, J,/,f) : Dent. Landw. PrcHsc, S3 

 (1906), No.'i. 02, pp. 727, 728; 100, pp. 7.S.'/, 7'.S';7).— Comparative ])ot tests during 

 1903 to 1905 with rye grass, oats, and celery on different kinds «t' moir soil are 

 reported, the two phosphates being tis(hI alone and in comliiii.-itinn witli kainit, 

 amnuHiium sulphate, and nitrate of soda, and also compared with superi)hos- 

 phate and bone meal. 



