778 
Journal of Agricultural Research 
Vol. V, No. 16 
The data in Table VIII show that calcium sulphate does increase the 
growth of the clover within a certain concentration. In amounts between 
0.02 and 0.05 per cent it appears to be most beneficial. The results 
also show that calcium sulphate increases the root development and the 
number of nodules. 
The effect of calcium sulphate on clover grown on Sparta acid sand 
was tested. Six kgm. of the sand admixed with 1 gm. of dipotassium 
phosphate were placed in each of ten 1-gallon jars. The composition of 
the Sparta acid sand used was as follows: 
Per cent. 
Potassium.*. 1.16 
Nitrogen.062 
Phosphorus.034 
Organic matter. 1. 51 
The jars were kept in the greenhouse and the moisture content held 
at 18 per cent. Each jar was seeded to red clover and then inoculated 
with a pure culture of red-clover organisms. After two weeks the jars 
were thinned to 20 plants in each. The plants grew luxuriantly, but 
there was no apparent difference in size until the sixth week. In jars 
7 and 8, to which 0.05 per cent of calcium sulphate had been added, the 
increase in growth was considerable, while in jars 9 and 10, to which 
0.1 per cent of calcium sulphate had been added, there was no appre¬ 
ciable increase. The jars to which 0.01 and 0.02 per cent of calcium 
sulphate had been added showed an increase in growth, but this increase 
was less than in jars 7 and 8. The green and dry weights of the clover 
were taken. The average weights of the clover are given in Table IX. 
Table IX .—Effect of calcium sulphate on red clover grown in Sparta acid sand 
Treatment. 
Weight of crop. 
Green. 
Dry. 
Untreated .. 
Gm. 
no. 6 
I 3 I - 1 
146. 7 
168. 5 
145.8 
Gm. 
19.4 
21. 2 
21. 7 
24. 6 
17-5 
Given .01 per cent of calcium sulphate. 
,02 per cent of calcium sulphate. 
05 per cent of calcium sulphate. 
10 per cent of calcium sulphate. 
These results show that calcium sulphate increases the growth of 
clover grown on Sparta acid sand. The increase, however, is confined 
to certain concentrations. The greatest increase was obtained at con¬ 
centrations of 0.02 and 0.05 per cent. 
EFFECT OF ELEMENTAL SULPHUR ON GROWTH OF RED CLOVER 
For this experiment ten 1-gallon jars, each containing 6 kgm. of 
Miami silt-loam soil, were used. Various amounts of sulphur were 
added. The jars were kept in the greenhouse and the moisture content 
