17 



out to tea. The most surprising point *of all is the fact that where 

 tea is being put out no trouble has often been taken to ascertain 

 the nature of the subsoil. 



CHARACTER OF THE SUBSOIL. 



I cannot too strongly insist on the character of the subsoil being 

 known by every manager for a good distance down. A distinguish- 

 ed American authority, *speaking of a district which, while absolutely 

 differing from that of Assam in many things, yet resembles that 

 of the lower valley in some respects, writes relative to this matter. 

 " It cannot be too strongly insisted upon that in our * * climate 

 farmers should make themselves more thoroughly acquainted with 

 their subsoil sown to the depth of at least four, but preferably six or 

 eight feet." This may be said to be practically a necessity of 

 practical agriculture where a large part of the root action is to be 

 carried on at a good depth. To take an example. I have in my 

 mind one or two gardens on the North Bank of the Brahmaputra 

 which are composed of fine light sandy loam, but within a few 

 feet of the surface there is a bed of impermeable clay blue in 

 colour and stinking in character. For some years the tea does 

 well, Then it receives a check, and sometimes when not more 

 than ten years old begins to deteriorate. The roots have, in fact, 

 touched the above clay layer, been thrown back into the com- 

 paratively shallow good soil, the plant food in this used up, and 

 deterioration commences. The result is inevitable on such a soil, 

 and I look upon these gardens put out on sand overlaying clay 

 of this sort as probably likely to be as short lived, without manure, 

 as any in the valley. 



Undoubtedly the best circumstances are those in which a sub- 

 soil of the same physical type as the surface exists for a great 

 depth. Such is one of the reasons which gives its pre-eminence to 

 the Doom Dooma ridge, There we dug eighteen feet, and the 

 soil was still the same somewhat sandier perhaps but of the same 

 general character nevertheless. Such is also the Tezpore Bank 

 the soil seems practically of the same character right down to the 

 ordinary patta level. The same occurs in parts of Jorhat and 

 no doubt in many other places. But such can only be the case under 

 exceptional circumstances and especially in very sandy soils. In 



* Hilgard. 



