374 V. KOZAI, M. TOYONACIA AND M, NAGAOKA. 



In their main features, the results of each experimental j-ear 

 agree not only with each otiier but also with those obtained in 

 the three preceding years, which may be quoted here for the sake of 

 comparison. 





Straw. 

 Grms, 



Full grain. 

 Gnus. 



Empty 

 grain. 



Grms. 



\Yhole 

 crop. 



Grms. 



1SS9 ; Variety Satsuiiia. 













197 



106 



6 



310 





193 



90 



6 



289 





459 



367 



15 



841 





714 



564 



24 



1302 





832 



575 



3 1 



1438 



1S90 ; \'aricty Shiratama. 













325 



277 



2 



604 





358 



261 



3 



621 





536 



413 





952 





770 



5S3 



s 



1 36 1 





975 



63S 



s 



1621 



iSqi ; Variety Koiiiwa. 













290 



213 



3 



506 





371 



271 



5 



647 





476 



341 



5 



S22 





730 



415 



1 1 



1056 





7S0 



576 



9 



1365 



Thus wc sec, tliat of the three important ingredients of i)lant 

 food, phosphoric acid is present in our soil in the minimum, and 

 that a partial manuring with nitrogen and potash does not bring 

 about any considerable augmentation of yield over the plots not 

 supplied A\ ith an}- fertilizing substance. The stock oT nitrogen in 

 the soil is not so poor as that of i:)hosphoric acid but it is far from 

 being sufficient to meet the requirement for maximum j'ield. The 

 supi>ly of soil potash, too, is not sufficient for maximum production, 

 but of the three essential nutriments, it is the most abundant. 



