P 2 5 ). All phosphates were ground to about the same degree of 
fineness. Each pot received an application of nitrogen as sodium 
nitrate and blood, potash as potassium sulphate, and lime as calcium 
carbonate. The lime was added to counterbalance any influences 
which the basic material in the slag might exert, and was added in 
excess of the lime requirement as determined by the Veitch method. 
The crops used included Japanese millet, cowpeas, buckwheat, 
radishes, and turnips. 
Fertilizer applications are represented in the table as follows : 
N = 0.06 per cent nitrogen from blood and 0.01 per cent from 
sodium nitrate. 
N 1J4 = 0.09 per cent nitrogen from blood and 0.015 per cent from 
sodium nitrate. 
K = 0.10 per cent potash (K 2 0) from potassium sulphate. 
11^ = 0.15 per cent potash from potassium sulphate. 
Ca = 0.10 per cent calcium carbonate plus that required by the 
Veitch method. 
Ca x = 0.15 per cent calcium carbonate plus that required by the 
Veitch method. 
P^ = 0.007 per cent phosphoric acid (P 2 5 ) from the phosphate 
indicated. 
P x , P lM , P 2 = 0.014, 0.021, and 0.028 per cent phosphoric acid, 
respectively. 
L = legumes. 
In one series of the experiments, green manure in the form of 
well-macerated cowpea vines was added at the rate of 2 ounces per 
pot; in the other no green manure was added. All applications were 
made in duplicate two weeks before seeding. The pots were watered 
daily. 
EXPERIMENT I. 
In the first experiment, soil No. 2 was used, a heavy clay soil very 
deficient in available phosphoric acid. In Table II are given the 
numbers of the pots, kind and amount of fertilizer added, weight 
of crop both green and dry, weight of heads, and plants per two 
pots. The first crop, Japanese millet, was planted July 31 and 
harvested October 20. The soil was then dried out, aerated, returned 
to the pots, and planted to cowpeas November 17. This crop was 
cut on January 17, weighed (each pot separately), and returned to 
the respective pots. Without any further addition of fertilizer the 
pots were planted to buckwheat February 6, which crop was har- 
vested March 27. The soil was again dried out, well aerated, and 
again planted to millet May 18, without further addition of fertilizer. 
This crop was harvested on August 10. The soil was again dried, 
aerated, and well mixed as above, and after a full application of ni- 
trogen and potash, but no phosphoric acid, was again planted to millet. 
61185°— 16 2 
