May 19, 1923 
Nitrogenous Fertilizers Influencing Chlorosis in Rice 625 
Analysis of moisture free soil 
Constituents. 
Per cent. 
Material insoluble in HCl (sp. gr. 1.115). 
68. 73 
9 - 43 
12. 32 
. 17 
Ferric oxid (Fe^Oo).. t.T!. 
Aluminic oxid (AI2O3). 
Manganese oxid (MnO).■. 
Lime (CaO).. 
2. 02 
Magnesia (MgO). 
I CO 
Potash (K2O). 
A. 
. 20 
Soda (NaaO). 
• 38 
. 07 
Phosphorus pentoxid (PoOc). 
Sulphur trioxid (SO3). 
Trace. 
•37 
07/1 
Carbon dioxid (CO2). 
Nitrogen (N).. 
Loss on ignition. 
5 - 47 
Total. 
100. 29 
Preparatory to being used, the soil was put through a process to crush 
the lumps, and it was then passed through a screen (4 meshes to the linear 
inch). After being thoroughly mixed, 45 pounds of the air-dried material 
were then weighed into each of the required number of glazed earthenware 
pots having a 5-gallon capacity. No provision was made for drainage. 
All treatments were added in solutions with sufficient water to saturate 
the soil, and the pots were placed on cars permitting of the carriage to a 
screened inclosure for exposure during fair weather and to a glass house 
at night and during rains. 
Seed of the Wataribune variety was used for experimental plantings, 
a strain of which had been carefully selected for several generations for 
this purpose. Sufficient seed was planted to furnish about three times 
as many plants as were required, and the excess seedlings were removed 
so that the most thrifty plants would be well distributed in the pot. 
Plantings were made immediately after the treatments were added, and 
the soils were kept wet to the point of saturation until the plants were 
about 2 inches high. The soils were then flooded and kept covered to‘ a 
depth of I or 2 inches until the plants were cut. 
In a comparison made of several compounds to determine the best 
source of phosphorus for the soil, orthophosphoric acid (H3PO4) was 
found to ^ve satisfactory results. This form was, therefore, used in all 
the experimental work to obviate any interference by inert material 
which might mask the effect of other treatments. 
EXPERIMENT I.~<:OMPARISON OF AMMONIUM SULPHATE AND SODIUM 
NITRATE TO DETERMINE THEIR INFLUENCE ON THE DEVELOPMENT 
OF CHLOROSIS IN RICE 
Twenty-two pots of soil were given treatments of phosphoric acid and 
potassium sulphate to furnish each pot with 5 gm. of PgOg and 2 gm. of 
KjO. The nitrogen compounds were added in sufficient quantity to 
supply I and 2 gm. of nitrogen to the pots which received the lighter and 
the heavier treatments, respectively. 
Of the pots which received each treatment, one-half were sprayed by 
means of an atomizer every two days with a i per cent solution of ferrous 
sulphate, preliminary tests having shown that ferrous sulphate was as 
efficient for spraying purposes as was ferric chlorid or ferric citrate. 
Five plants were selected from the seedlings to remain in each pot. 
Table I gives the plan of the experiment and the significant results ob¬ 
tained from it. 
39364 - 23 -- 7 
