28 
MANURING EXPERIMENTS WITH PADDY RICE. 
nitrogen applied was recovered in the crop. The following 
calculation yields information on this subject. 
Nitrogen per tan . 
Unman¬ 
ured. 
With¬ 
out 
Nitro¬ 
gen. 
5 
kilo¬ 
grms. 
7.6 
kilo¬ 
grms. 
10 
kilo¬ 
grms. 
12.5 
kilo¬ 
grms. 
15-0 
kilo¬ 
grms. 
I 7-5 
kilo¬ 
grms. 
Nitrogen, grammes 
per plot : 
In the grain .. 
1.65 
4.46 
5.68 
6.30 
6.91 
7.24 
7.66 
7.71 
„ ,, straw .. .. 
2.06 
2.67 
4.10 
4 *- 
CO 
0 
O 
oo 
in 
6.07 
6.46 
6.86 
„ „ chaff .. .. 
0.13 
O.4I 
0.61 
0.64 
0.66 
0.65 
O.72 
o -73 
Total .. 
3-84 
7-54 
10.39 
n.74 
13-37 
ï3. 9 6 
14.84 
15-30 
In the crop pro¬ 
duced without ni- 
trog. manure 
7-54 
7-54 
7-54 
7-54 
7-54 
7-54 
Assimilated from the 
manure 
2.85 
4.20 
6.83 
6.42 
7 - 3 ° 
7.76 
Applied in the man¬ 
ure. 
_ 
4-59 
6.89 
g.18 
11.48 
Ï 3-77 
16.07 
Assimilated, per cent 
of the nitrogen ap¬ 
plied . 
62.r 
61.0 
63-5 
56.0 
53 -o 
48.3 
With moderate quantities of nitrogen, such as should be 
applied in practice, a very high rate of this nutrient has been 
consumed by the plants ; in the average of the first 3 trials 
(5, 7.5 and 10 kilogrms. of nitrogen) 62.2 % of the nitrogen 
given were recovered in the crop, a result which very nearly 
coincides with observations made by P. Wagner 11 on dry 
land, in which 64 % of that nutrient entered the crop. This 
result has important practical bearings, showing that ammoni¬ 
acal salts (ammonium sulphate, night-soil) can be safely ap¬ 
plied to paddy soils that have a good absorptive power for 
12 P. Wagner, Steigerung der Bodenerträge durch rationelle Stikstoff- 
düngung.2 . Aufl. 1888, p.68. 
