Manuring Experiments with Paddy Rice. 



{Fourth, Fifth anil Sixth W-ars : 1S92 — 1894.) 

 BY 



Y. Kozai, M. Toyonaga and M. Nagaoka. 



Assisla)it Professors of Agriciiltitral Chemistry. 



These experiments have been in progress since 1889 and 1890'" 

 and were carried on for the purpose of getting some information on 

 the following points : 



1) The exhaustion of soil nutriments by the successive culti- 

 vation of rice, and the quantity of the fertilizer required for the soil 

 to recuperate, as judged by the quantities of nutriments contained 

 in the crop. 



2) The after effect of unrccovcrcd phosphoric acid applied as 

 sodium phosphate. 



3) The after effect of various phosphatic manures. 



The method of experiments was exactly the same as in the 

 preceding }-ears. After cutting the rice, the plots which were sur- 

 rounded by deep wooden frames, were left untouched till the spring 

 of the next year. In the beginning of June, these plots were irrigated 

 and carefully stirred until the soil was converted into a fine uniform 

 mud. In the mean time, the young rice plants raised carefully in a 

 seed bed were transplanted after manuring the plots. Each plot 

 received 16 bundles each of 12 healthy plants. Irrigation was at 

 once commenced, the water being supplied from wooden tanks with 

 a capacity of about 70 litres each placed on the northern side of the 



1) These experiments were originally commenced in 1889 by Ilofrath, Prof. Dr. (>, 

 Kellner, formerly Professor of Agricultural Chemistry in the Imperial University, under 

 whose direction they were carried on till 1892, when he returned to Germany to succeed the 

 late Prof. Dr. G. Kiihn at Mockern experimental station. The results obtained up to that 

 dale have been already published by him in Die landwirthschaflliche Versuchs Stationen Vol. 

 39, (1891). p. 361, and Vol. 40, (1892) 295, as well as in this Bulletin, Vol. I. Xo. 8, Ko. 

 10, and No. ll. 



2) Bulletin Vol. I. No. lo, College of y\t,'ricuUure, Imperial University. 



