SOILS FERTILIZERS. 



623 



to 1914) on four plats equally and liberally fertilized as regards nitrogen, plios- 

 I)horus, and potassium, two of tlie plats receiving their nitrogen in ammonium 

 sulphate and the other two in sodium nitrate, and one of each pair receiving 

 slaked lime fi'om time to time. 



The results of the first eight years' experiments of this series have been 

 previously reported ( E. S. K., 15, p. G72). 



During the 22 years the plats received average annual applications of 44.5 lbs. 

 per acre of nitrogen in ammonium sulphate or sodium nitrate, 90 lbs. of phos- 

 phoric acid in dissolved boneblack or acid phosphate, and 114 lbs. of potash in 

 muriate of potash. The total application of lime during the period was G,3.50 

 lbs. ; 4,750 lbs. in two applications in 1893 and 1894, and 800 lbs. in 1902 and 

 again in 1912. 



The lime requirements of the soil at different dates as indicated by the Veitch 

 method were as follows: 



Lime rcqiiirementfi of different fertiiizer plats in IDO'/, JD12, and lOl'f. 



Kind of plat. 



Calcium oxid required per 

 acre of soil. 



1904 



1912 



1914 



Unlimed ammonium sulphate plat 

 Limed ammonium sulphate plat. . 



Unlimed sodium nitrate plat 



Limed sodium nitrate plat 



Lbs. 



4,700 



1,100 



2,500 







Lbs. 

 5,500 

 3,200 

 4,200 

 2,600 



Lbs. 

 7,784 

 4,607 

 4,210 

 3,069 



About 280 different kinds of plants have been grown upon the plats, classi- 

 fied as follows: Flowers (mostly perennials), 75; trees and small fruits, 25; 

 grasses and clovers, 30 ; and miscellaneous crops, 150. The behavior of the dif- 

 ferent plants as regards the condition of the soil are presented in concise tabu- 

 lar form. It is shown that the behavior of the different plants toward liming 

 is influenced to a marked extent by the lesidual effect of ammonium sulphate 

 and sodium nitrate. The plants tested included those representing all grades, 

 from such as are positively injured by an application of lime, even to a very 

 acid soil, to such as are unable even to live on an acid soil and are greatly 

 benefited by liming. 



Prominent among the flowers which seemed to be quite tolerant of soil acidity 

 were blue false indigo, marigold, tickseed, evergreen, Japanese bell flower, 

 Xicotiana, scarlet sage, and catchfly. Of the trees tested Norway spruce, birch, 

 and peach seemed to be particularly tolerant of soil acidity. Of the fruits the 

 Blackcap raspberry was more productive on the unlimed than on the limed 

 plats, whereas the opposite was true with the Cuthbert raspberry. The most 

 pronounced case of injury from liming was represented by the cranberry. 



Of the grasses redtop and Rhode Island bent grew well on the unlimed plats. 

 The growth of the clovers varied with the source of nitrogen, some of them 

 growing about equally well on the sodium nitrate plats whether lime was added 

 or not. With the exception of cowpeas, lupines, serradella, and vetch the 

 leguminous plants were, as a rule, however, benefited by lime. Japanese millet 

 seemed to grow best on the most acid soil. 



The conditions in these experiments were not such as to make it possible to 

 compare the relative efficiency of ammonium sulphate and sodium nitrate as 

 sources of nitrogen for the different crops since the reaction of the soil was not 

 9085S°— No. 7—15 3 



