53 



relative available richness of two soils in this material is to take the 

 proportion of the Potash to the clay present, and this clay may very 

 fairly be measured by the Oxide of Iron and the Alumina taken 

 together. Under these circumstances the Potash should not be less 

 than three per cent, of the Oxide of Iron and Alumina. The follow- 

 ing table shows for several gardens the percentage of total Potash, 

 and the proportion it bears to the clay measured as above. 



Any direct connection of either the yield or the quality with the 

 figures is not evident, and this is probably because there is a large 

 excess of Potash in almost all the Assam soils I have examined. In 

 fact there are only about three in the sixty or seventy soils in which 

 Potash has been determined in which it is markedly deficient. 



But as stated above, not by any means all the Potash in the soil 

 is immediately available. The following table shows the amount 

 actually available in the virgin and in the old tea soils of several 

 gardens. They show, if nothing else, the drain on this ingredient 

 which takes place in the growing of tea, and the necessity sooner or 

 later of Potash manures. The day when this will be required 

 is, however, I fancy, still far off in most cases. 



