18 REPORT OF THE AGRICULTURAL RESEARCH INSTITUTE 



lier stages the leaves are practically twice as rich in this 

 element as the stems. As the ears form, both the stems and 

 the leaves lose nitrogen. By the time that the grains " fill 

 up " the nitrogen accumulates most in the grain while in 

 the other parts of the plant it falls to the uniform level of 

 about a third of what is present in the grains. It seems 

 therefore that there is a tendency for the nitrogenous matter 

 to press forward towards the top of the plant. 



3. The configuration of the curve of the content of phos- 

 phoric acid at the different stages indicates that the amount 

 of this plant food available for the rice plant at Sabour was 

 low throughout. 



4. The percentage of potash in the above-ground parts 

 increases from the first stage to the preflowering stage from 

 whenceforward there is a decline. In the roots also there 

 is a continued fall after the second stage. 



5. As the ears form and mature there occurs a concen- 

 tration of nitrogen, phosphoric acid and potash in the 

 grains at the expense of the other parts of the plant. 



6. The assimilation of nitrogen, phosphoric acid and 

 potash by the plant is fairly complete by the time flowers 

 appear. Hence enough plant foods must be available for 

 the plant during the early stages. 



7. There does not seem to be any migration of the 

 absorbed nitrogen and potash back into the soil. 



8. Taking the yield of a crop of rice as 900 lb. of dry 

 grain, the soil suffers a depletion of 29-33 lb. nitrogen, 9-64 

 lb. phosphoric acid and 49-69 lb. potash per acre by the 

 removal of the grains and straw. 



Feeding value of the different parts. As to the feed- 

 ing values of the different parts of the rice plant, as cal- 

 culated from the chemical analysis at the various stages, it 

 was found that the straw declines in value with the age of 

 the plant but there is no difference in nutritive value 

 between ripe and dead ripe plants. The leaves are more 

 nutritious than the stems of the same period. The leaves 

 in the preflowering and the flowering stages are about 



