16 
IMPERIAL COLLEGE OE 
the effect of the nitrate has been to increase the weight of 
straw (or decrease the weight of grain) to the whole crop. 
What effect it had on the tillering of the plants could not well 
be ascertained as the crop stood somewhat thick in the rows 
and the original plants could not be pointed out. It is 
interesting to note that there is less grain iu proportion to the 
straw in a crop of upland rice than there is in a crop of irrigated 
rice. The average per cent, of grain on the unmanured plats 
of the former was 43.78, leaving 56.22 o/o of straw, an excess 
of straw equal to 12.44 o/o; or the grain is to the straw as 
100 :128. On unmanured paddy land the grain was to the 
straw as 100: 104. This does not include the roots in either 
case. 
Potash and superphosphate at the rate pr. acre of 140 lbs. 
and 244 lbs. respectively produced the highest yield on plat 
14, equal to about 50 bushels pr. acre. Plat 2, similarly 
manured, but with only half the quantity, produced at the 
rate of 44 bushels. The increase of 6 bushels must be 
credited to the greater quantity of manure on the former plat. 
It is to be noticed, however, that in four cases, the yields in 
series B falls below the yields on the corresponding plats in 
series A, which received less manure. How is this to be 
accounted for? In two of those cases the manure contained no 
superphosphate, in one cass it was supplied in but moderate 
quantity, (120 lbs. pr. acre on plat 23) ; while in only one case 
was it present in a quantity corresponding to that of the 
potash, 244 lbs. pr. acre on plat 16. But in all four cases 
carbonate of potash was supplied at the rate of 140 lbs. It is 
possible that 140 lbs. of this somewhat caustic substance was 
too much for the good of the plants, but that in the cases where 
superphosphate was also supplied in considerable quantity, a 
reaction may have set in to ameliorate its action on the plant; 
the free sulphuric acid of the superphosphate, uniting with a 
portion of the potash to form the neutral sulphate of potassium. 
Used in moderate quantity, potash had decidedly a beneficial 
influence on the yield. 
Superphosphate also increased the yield. And the same 
