MULCHED-BASIN SYSTEM OF IRRIGATED CITRUS CULTURE. 15 
mulched, (2) surface soil left undisturbed, (8) seeded to barley, 
(4) covered with about 2 inches of alfalfa mulch. The soil con- 
tained 19.2 per cent of moisture when the cans were filled. The cans 
_were weighed from time to time to determine the moisture loss, but 
only the final results need be given here. On August 8, 38 days 
after the initial weighing, the moisture content of the soil in the 
different cans was as follows: (1) Surface soil mulched, 14 per 
cent; (2) surface left undisturbed, 10.1 per cent; (8) seeded to 
barley, 3.1 per cent; (4) mulched with alfalfa, 18 per cent. The 
soil seeded to barley had reached the wilting coefficient by July 16, 
21 days after the seed was planted. 
These results show the relative effectiveness of a soil mulch and 
an alfalfa mulch in retaining moisture. The soil under the alfalfa 
mulch had lost but 1.2 per cent of moisture, while the soil under the 
dust mulch had lost 4 per cent, or over three times as much as the 
alfalfa-covered soil. The soil mulch in this test was, furthermore, 
kept in a much more effective condition than is practicable in a 
grove. 
EFFECT OF BASINING ON TREE GROWTH. 
THE SUNNY MOUNTAIN GROVE. 
On the light soil of the Sunny Mountain experimental grove it 
was nearly a year before any very noticeable change occurred in the 
appearance of the mulched trees, but during the autumn of 1914 there 
was a distinct advance in the new growth on the trees in the basins as 
compared with the check trees. 
The grove was badly infested with scale, for which it was fumi- 
gated in the fall of 1914, at a time when the new growth on the 
basined trees was well advanced. The basined trees, on account of the 
larger amount of new growth, were injured more by the fumigation 
than the check trees, but the trees soon recovered and again grew 
faster than the check trees. The beneficial effect of the mulched-basin 
treatment was also plainly in evidence on the untreated rows of trees 
immediately adjoining the experimental tract, showing that the root 
systems extend laterally to adjoining tree rows when conditions are 
favorable. 
THE VICTORIA GROVE. 
The portion of the grove used for these experiments had been pre- 
viously used as an experimental plat and had received sodium nitrate 
only as a fertilizer for four years. This experiment was terminated 
in 1913, and the plat was manured in 1914. The trees were in an un- 
thrifty condition in 1914 and 67 per cent of the leaves were mottled. 
The trees were heavily pruned in the winter of 1914-15, so that the 
