Apr. 19 ,1924 Orange Trees and Nutrient Solution Concentrations 
283 
THE ASH OF TREES GROWN IN SOIL 
The foregoing pages have discussed the composition of trees grown in sand 
cultures to which nutrient solutions were added. We shall present similar data 
upon trees grown in soil (Table VI). The results are also given for the water 
solubility of the inorganic constituents of the dry matter. The dry matter was 
placed on a quantitative filter paper in a funnel and was washed with distilled 
water until approximately 600-800 cc. of filtrate were obtained. After each 
application of distilled water to the dry matter, the distilled water was not 
renewed until the filtrate ceased dropping from the funnel. The filtrate was 
evaporated to dryness in a porcelain dish and ignited at low heat. 
The ash obtained from the filtrate after leaching the dry matter of the various 
parts to the trees decreases as we pass from the leaves to the rootlets, where the 
solubility is approximately that of the shoots. The ash obtained from the 
filtrate of leached leaves constituted 57 per cent of the total ash found in the entire 
dry matter of the leaves. There is considerable water-soluble sodium in the 
leaves, but it remains fairly constant at a lower value in other portions of the 
trees. However, the actual amounts of sodium present in these trees are rela¬ 
tively small. 
The solubility of calcium deserves particular attention, only 45.82 per cent 
being soluble in the leaves, 15.03 per cent in the shoots, while the trunk, root* 
and rootlets contained only 7 to 9.5 per cent soluble calcium. 
In comparing these trees with those from the sand cultures (Table V) one sees 
that the percentage of potassium was lower in the trees from the soil, while that 
of calcium was higher. The solubility of sodium was less in the ash of the trees 
from the soil and that of calcium was slightly higher. With the exception of 
the rootlets, the sulphates and phosphates were more soluble in the trees from 
the soil than in those from the sand cultures. 
Table VI.— Data on the composition of orange trees grown in soil; analysis of 
the ash and the water-soluble fractions of the dry matter 
Leaves 
Shoots 
Trunk 
Root 
Rootlets 
Per¬ 
cent¬ 
age 
Solu¬ 
bility 
Per¬ 
cent¬ 
age 
Solu¬ 
bility 
Per¬ 
cent¬ 
age 
Solu¬ 
bility 
Per¬ 
cent¬ 
age 
Solu¬ 
bility 
Per¬ 
cent¬ 
age 
Solu¬ 
bility 
Nitrogen in the dry 
matter. 
1.94 
0.85 
0.52 
0.51 
1.19 
# 
Ash in the dry mat¬ 
ter. 
13.96 
57.02 
5.90 
39.10 
2.34 
35.71 
2.37 
27.42 
8.06 
40.66 
Ash constituents: 
Na. 
2.06 
83.30 
3.71 
62.82 
5.42 
57.24 
7.59 
66.74 
2.91 
64.87 
K . 
8.43 
99.24 
9.52 
97.24 
12.34 
96.93 
8.01 
92.94 
13.53 
95.18 
Ca. 
28.16 
45.82 
28.01 
15.03 
23.51 
8.69 
19.60 
7.18 
ia 18 
9.39 
Mg . 
2.51 
85.84 
2.90 
67.16 
2.34 
4& 59 
1.69 
36.45 
2.70 
67.92 
Cl__ 
0.28 
100.00 
0.41 
100.00 
0.74 
100.00 
1.43 
100.00 
4.67 
99.20 
S04. 
4.64 
81.73 
4.16 
73.88 
4.43 
55.22 
4.54 
47.25 
11.30 
75.97 
PO 4 . 
3.29 
94.58 
6.50 
90.09 
7.71 
76.96 
9.32 
63.64 
5.18 
58.55 
SUMMARY 
(1) The sap expressed from leaves of orange trees showed remarkable con¬ 
stancy in the concentration of solutes and in hydrogen-ion concentration, al¬ 
though grown in nutrient solutions of differing composition. 
(2) Orange seedlings grown in water cultures, ranging in concentration from 
364 to 3,635 parts per million of solutes, indicated that the most favorable con- 
