jom of Afflcoinm research 
DEPARTMENT OF AGRICULTURE 
Vol. V Washington, D. C., November 29, 1915 No. 9 
ASH COMPOSITION OF UPLAND RICE AT VARIOUS 
STAGES OF GROWTH 
By P. L. Gile, Chemist , and J. O. Carrero, Assistant Chemist, Porto Rico Agricultural 
Experiment Station 
INTRODUCTION 
The following ash analyses of upland rice (Oryza sativa) at various 
stages of growth were made in connection with a study of the effect of 
lime-induced chlorosis on the ash composition of the plant. In the course 
of this work it was necessary to know particularly how the iron content 
of the plant varied with its age.. The analyses are reported here, as it 
is believed that such data are of general importance in explaining cer¬ 
tain peculiarities of crop growth. 
Kelley and Thompson 1 have already investigated the composition of 
rice at different stages of growth, but their study did not suffice for our 
purpose, as it covered only the last half or third of the growing period 
and did not include iron and some other ash constituents. 
EXPERIMENTAL METHODS EMPLOYED 
The plants were grown in large cylinders sunk in the ground and 
protected by wire netting (4 meshes to the inch). Each cylinder afforded 
a surface of 7 square feet of soil in which 29 plants were grown. 
Porto Rican red-clay soil, which is well adapted for rice, was used in 
the cylinders. This was fertilized liberally with sulphate of ammonia, 
acid phosphate, and muriate of potash, so that the ash composition might 
not be influenced at any stage by a lack of nutrients. Fertilizers furnish¬ 
ing 10 gm. of nitrogen (N), 5 gm. of phosphoric acid (P 2 0 6 ) and 10 gm. of 
potash (K 2 0 ) were incorporated with the soil before planting; when the 
plants were 18 days old, a surface application of 2 gm. of nitrogen, 1 gm. 
of phosphoric acid, and 2 gm. of potash was made; and when the plants 
were 59 days old, 3 gm. of nitrogen, 3 gm. of phosphoric acid, and 3 gm. 
of potash were applied. 
1 Kelley, W. P., and Thompson, Alice R. A study of the composition of the rice plant. Hawaii Agr. 
Exp. Sta. Bui. 2i, si P- 1910. 
Journal of Agricultural Research, 
Dept, of Agriculture, Washington, D. C. 
Vol. V, No. 9 
Nov. 29,1915 
