MANURING EXPERIMENTS WITH PADDY RICE. 



397 



acid contained in this manure warrants its application for soils with 

 a medium absorptive power, since in soils w/th a low absorptive 

 power too great distribution is effected while in those with a high 

 absorptive power, a rapid conversion into basic compounds takes 

 place, neither of which is fav^ourable to the absorption of phosphoric 

 acid by plants. 



(3.) The two kinds of bone manure, steamed bone dust and 

 crude bone dust, were also very effective. Of these steamed bone 

 dust proved to be somewhat less effective than crude bone dust in 

 the first year, probably owing to the loss of some of its gelatinoid 

 substance ; but in subsequent years the former acted a little better, 

 so that the two became axactly same in effect. These manures 

 acted somewhat rapidly and showed excellent-results for surpassing 

 those observed by European investigators. The same results were 

 observed still more distinctly in our experiments on the upland 

 soil."' This proves that in countries with warm climate and 

 copious rain as in this country bone measures may be used in a 

 crude state with advantage. 



(4.) Thomas phosphate was found to have a long continued 

 action, its effect being still observable in the fifth year after its 

 application. This manure was a little inferior to bone manures in 

 the first year, but in subsequent years it acted better so that when 

 the after effect is taken into account, its effect is a little greater than 

 tliat of bone manures. 



(5.) Peruvian guano, bone ash and phosphorite were also found 

 to have a long continued action, but it was very slow, in spite of the 

 richness of our paddy soil in acid humus which favours the de- 

 composition of insoluble calcic phosphate. 



(I) This EulIeUiii Vol. I. No. 12. 



