JOURNAL OF ACRKULTURAL RESEARCH 
DEPARTMENT OF AGRICULTURE 
Vol. VII Washington, D. C., December 18, 1916 No. 12 
ASSIMILATION OF IRON BY RICE FROM CERTAIN 
NUTRIENT SOLUTIONS 
By P. L. Gile, Chemist , and J. O. Carrero, Assistant Chemist , Porto Rico Agri¬ 
cultural Experiment Station 
INTRODUCTION 
It has long been recognized that on calcareous soils certain plants do 
not make a normal growth and are often affected by chlorosis This 
has been variously ascribed to the physical condition of the soil; an 
increasing assimilation of lime by the plant; a diminished assimilation of 
potash, iron, or phosphoric acid; or a diminished assimilation of all mineral 
nutrients due to the neutralization of acid root excretions. As already 
noted, work at this station with pineapples and upland rice indicated an 
insufficient assimilation of iron as the principal cause (4, 5) 1 
As calcareous soils have a slightly alkaline reaction it is important to 
know whether plants intolerant of calcareous soils are sensitive to an 
acid or alkaline reaction per se, and whether the reaction of the soil has 
any effect on the assimilation of iron. Various experiments with upland 
rice {Oryza saliva) in nutrient solutions and soil cultures have been con¬ 
ducted to gain information on this subject. The experiments with nutrient 
solutions reported here show the effect of the quantity and form of iron 
and reaction of the nutrient medium on the asssimilation of iron by rice. 
PLAN AND EXPERIMENTAL METHODS 
The plan of the work was to measure the growth of rice in acid, neutral, 
and alkaline nutrient solutions when supplied with 0.002 and 0.008 gm. 
of iron (Fe) per liter from ferrous sulphate, ferric chlorid, dialyzed iron, 
ferric citrate, and ferric tartrate; to determine the amount of iron taken up 
by the plants from these solutions; and to determine the amount of soluble 
iron actually present in the solutions at different times. A few other ex¬ 
periments were conducted to explain certain results obtained. Three 
preliminary experiments were also conducted before the general plan and 
exact detail of the experiments were decided upon. 
1 Reference is made by number to 'Literature cited/* p. 528. 
Journal of Agricultural Research, 
Depth of Agriculture. Washington, D. C, 
gm 
Vol. VII, No. is 
Dec. x8,19x6 
B—12 
(503) 
